Program

Abstract
The pursuit of enhancing the mechanical performance of tungsten for extreme environments is often constrained by the material’s brittleness, which facilitates intercrystalline fracture. A promising pathway to overcome the strength-ductility tradeoff is through grain refinement to the ultrafine-grained or nanocrystalline regime. Such microstructures are sensitive to grain-boundary chemistry, where small amounts of specific elements can enhance or degrade mechanical properties. Tungsten thin films are synthesized using magnetron sputtering, containing doping elements which are predicted to enhance grain boundary cohesion. Focused ion beam milling is used to prepare microcantilevers, which are tested in-situ within a scanning electron microscope using a micromechanical testing system. Compositions with superior mechanical properties are selected for scaling up ultrafine-grained tungsten materials, which is achieved through nanopowder sintering. Tungsten nanopowder is synthesized through solution combustion synthesis and reduction, followed by processing via spark plasma sintering. The mechanical properties of sintered materials containing different doping elements are characterized using micromechanical testing. Specific elements substantially enhance mechanical properties of investigated nanostructured tungsten materials, indicating a link between grain boundary chemistry and mechanical performance.

Abstract
The production of large-scale components based on refractory metal-alumina composites for high-temperature applications suffers from two counteracting facts related to the porosity of the materials: (i) high electrical and thermal conductivity for dense materials, and (ii) lower strength but concurrently lower shrinkage for materials with lower density. The presentation gives an overview on the high-temperature mechanical properties of refractory Nb-Al2O3 composites with 60 vol.% Nb and 40 vol.% Al2O3 manufactured by different production routes as a function of the grain size and the resulting porosity under compressive loading up to 1300°C. Thus, a comparison of the compressive behaviour of (i) fine-grained cast material, (ii) coarse-grained cast material based on presynthesized granulates, (iii) extruded material, (iv) cast material based on alumina powders of particle grain sizes, and (v) field-assisted sintered (FAST) material is given, whereas materials (i) to (iv) were pressureless sintered. The experiments revealed a high plasticity of all pressureless sintered composite variants at high temperatures related to the high porosity, whereas the FAST materials showed the higher strength at concurrently lower plasticity.

Abstract
Refractory high entropy alloys (RHEA) that mimic the microstructures of state-of-the-art, Ni-based superalloys with A1 matrix and L12 precipitates can consist of a disordered A2 matrix and ordered B2 precipitates. These alloys are promising candidates for high-temperature applications because of their high melting points. Despite the considerable efforts to develop A2-B2 RHEA, there is currently no systematic assessment of the creep behavior and deformation mechanisms of such alloys. 27.3Ta-27.3Mo-27.3Ti-8Cr-10Al (in at. %) is a relevant example of such a microstructure formed by a precipitation reaction and remains stable even close to the solvus temperature. Compression creep tests were conducted at temperatures of 1000 °C and above with varying constant true stresses to unveil the creep response. Subsequently, scanning and transmission electron microscopy were employed to examine the deformed microstructures and to identify the underlying mechanisms at different creep strains. Compared to poly-crystalline, single-phase A2 or B2 RHEA, a substantially higher creep resistance is observed for the two-phase alloy while minimum creep rates even comparable to those of single-crystalline A1-L12 CMSX-4 are found.

Abstract
High-entropy alloys (HEAs) typically consist of at least five elements in similar concentrations each and proved outstanding properties or combinations of properties, e.g. both strength and ductility, compared to conventional alloys. Developing HEAs from refractory metals (RHEAs) offers a high potential for innovative high-temperature materials with capabilities exceeding state-of-the-art Ni-based superalloys which are limited to long-term temperatures of 1100 °C.
In contrast to conventional refractory metals and alloys, the equiatomic RHEA AlCrMoTaTi proved a high oxidation resistance comparable to Ni-based superalloys. In this work, this RHEA is systematically varied in its Al, Cr and Ti concentrations in order to improve its material density, oxidation resistance and microstructure. The non-equiatomic derivatives AlxCryMoTaTiz are processed by powder metallurgy and investigated with regards to formed phases, microstructure, isothermal oxidation resistance and mechanical properties.
CALPHAD simulations predict solidus temperatures of 1500…1900 °C, well beyond Ni-based superalloys. All Al and Ti derivatives form protective chromia and alumina oxide scales and there are indications for CrTaO4 formation. For Ti derivatives, internal nitridation was found.

Abstract
Chromium alloys are being considered for next-generation concentrated solar power applications operating >800C (http://compassco2.eu). Cr offers advantages in melting point, cost, and oxidation resistance. However, improvements in mechanical performance are needed for high temperature strength, creep and wear resistance. Here, a ‘bcc-superalloy’ approach has been investigated where the bcc Cr(Fe) matrix is strengthened by ordered-bcc NiAl intermetallic precipitates, with iron additions used to tailor the precipitate volume fraction and mechanical properties at high temperatures.

Computational design using CALPHAD identified Fe additions to increase the solubility of Ni and Al within bcc-Cr, to increase precipitate volume fraction. Thermal ageing developed nano-scale, highly-coherent B2-NiAl precipitates with lattice misfit ~0.1% within the Cr(Fe) matrix. The Cr(Fe)-NiAl A2-B2 alloys show remarkably low coarsening rate (~102 nm3/h at 1000°C), outperforming ferritic-superalloys, cobalt- and nickel-based superalloys. The alloys also show high compressive yield strength of ~320 MPa at 1000°C. Microstructure tailoring with Fe additions offers a new design route to improve the balance of properties in “Cr-superalloys”, accelerating their development as a new class of high-temperature materials.

Abstract
Refractory metals and alloys typically do not grow intrinsic protective oxides but instead show catastrophic high temperature oxidation. At temperatures as low as 500°C, Nb, Ta, or Mo start to oxidize catastrophically by the formation of voluminous or volatile oxides. Recently high entropy or compositionally complex refractory alloys have shown potential as candidates for high temperature structural materials as they exhibit significantly higher strengths than conventional alloys with potential oxidation resistance. For example, the Cr-Ta-Ti-Al-Mo system demonstrated oxidation resistance which was attributed to the formation of thin and continuous CrTaO4 below a mixed oxide scale. This chromium tantalate has been shown to form continuous and rather slow-growing layers in a variety of high temperature oxidation resistant alloys even including Ni-based superalloys as part of a more complex oxide scale. The formation mechanism(s) of a pure CrTaO4 were investigated by using the model alloy Cr-20at.%Ta in Ar-2.5vol.%O2 at 1000°C. As this tantalate exhibits the rutile crystal structure, the Cr-20at.%Ta material was additionally alloyed with small quantities of elements exhibiting different valences in the lattice to achieve a doping effect and investigate its influence on oxygen diffusion through the lattice.

Abstract
In the MoSiB system, the berczik triangle has been established to describe a three-phase field to form tough and strong high-temperature materials. During solidification molybdenum usually solidifies first forming islands resulting in an intermetallic matrix and brittle material behaviour. Surprisingly, after PBF-EB ductility has been found at temperatures T >= 800 °C accompanied by an extremely high bending strength exceeding 1200 MPa, as reported previously [1]. This strength is retained up to 1100 °C. The PBF-EB conditions allow for the formation of a very fine microstructure which is then annealed due to preheating the building chamber during the remaining build job time. This causes significant, although not drastic changes in the microstructure over the building height of the samples. Those changes in microstructure as well as the effects achieved after hot-isostatic pressing will be addressed in the talk. The main findings are that dendritic growth may lead to a metallic matrix, and short diffusion paths result in a low concentration of silicon at the grain boundaries.

[1] U. Gaitzsch, et al., Intermetallics 2023: 37–38.

Abstract
Promising candidates for high-temperature applications include Cr-rich Cr-Si alloys due to their high melting point, low densities, and higher worldwide resources of Cr and Si. This work examines binary, ternary, quaternary, and quinary alloys with Cr concentrations up from 89 at.%, which feature an A2 Cr solid solution matrix and strengthening A15-phase precipitates. To address the limitations of Cr-based alloys — such as inadequate oxidation resistance due to oxide scale spallation, embrittlement from nitride formation, and low ductility — alloying with Ge, Mo, or Pt was found to be highly beneficial. Ge stabilizes A15-phase formation and improves oxide scale adhesion even under cyclic exposure. Pt binds nitrogen by forming an antiperovskite phase instead of a brittle Cr2N layer and increases the alloy’s hardness most by solid solution hardening. Mo decreases the creep rate, ductility, and nitridation resistance of the A2 matrix phase. This work focuses on alloys fabricated by casting using an electric arc furnace for small ingots, followed by scaling up to around 400 g ingots via vacuum induction melting.

Abstract
The demand for new high-temperature materials to increase the operating temperatures and thereby enhancing the efficiency of energy conversions systems is growing. Mo-Si-Ti alloys have gained attention for their remarkable oxidation and creep resistance, making them suitable for applications at temperatures beyond those of Ni-based alloys. Mo-Si-Ti alloys, specifically the eutectic composition Mo-20Si-52.8Ti (at%), provide a well-balanced combination of properties, offering both effective oxidation resistance and improved creep resistance. The composition yields a body-centered cubic disordered Mo-rich solid solution and an intermetallic hexagonal (Ti,Mo)5Si3 phase. The composition, distribution, and size of the phases can vary significantly based on the processing method used, such as arc melting or additive manufacturing. These variations affect the mechanical properties due to the complex interaction of various strengthening mechanisms, including solid solution strengthening and precipitation strengthening. In this study, the mechanical properties of eutectic Mo-Si-Ti produced under different conditions are examined through macromechanical testing. Additionally, nanoindentation testing is conducted to gain a deeper understanding of the material's mechanical behavior.

Abstract
The future of manufacturing is net zero and circular. The industrial sector is pivotal in this sustainable transition, as it is responsible for 25% of global greenhouse gas emissions (IEA, 2022) and a key driver of global waste growth (World Bank). Key challenges to drive industrial sustainability include data management, hotspot analysis, and recycling technology, which make sustainability efforts resource intensive through ineffective allocation, manual work, and lost material. To begin to address these challenges for hard metal powder and tools, Sandvik Machining Solutions initiated Life Cycle studies. After an initial pilot study  by Seco, it was found that hard metal powder is the largest environmental impact contributing to 55% of the turning inserts global warming potential. Virgin WC powder contributes 25% to the total impact, compared to 19% from chemically recycled material and less than 1% from zinc reclaimed recycled material. Therefore, life cycle management driving sustainable powder through improved recycling infrastructure, circular business models and collaboration across the value chain holds the key to net-zero and circularity for the hard metal industry.

Abstract
Recycling of CRMs/SRMs as tungsten and cobalt is mandatory for the European industrial economy. Electrochemical methods to recover those metals from hardmetal scrap, although widely studied, never reached the productivity level of common industrial processes. In recently published work, we demonstrated – at laboratory scale – an innovative and eco-friendly electrochemical recovery process - that is the object of a recent MESCEL EIT-Raw Materials funded project - to circumvent hardmetal pseudopassivation with alloy-bounded corrosion-resistant grades. As verifying the validity of the protocol in non-laboratory conditions is important to fully assess its potential for industrial applications, in this work the protocol is applied with a realistic electrochemical cell configuration, extending the approach from dedicated laboratory samples to objects that mimic real-life scrap, including edges and irregular surface variations. The results show that productivity increases, although the presence of edges introduces mechanical instability in the surface rejuvenation process and uneven current density lines distribution, preventing uniform material extraction across the entire surface. These results highlight the protocol validity and lay the foundation for further optimization towards pilot plant implementation.

Abstract
For over 20 years, the Chair of Nonferrous Metallurgy has been at the forefront of cemented carbide recycling, testing different options such as direct and semi-direct processes. Through extensive research and collaboration with industry partners, significant expertise has been built up, particularly in the optimisation of the zinc process in both liquid and gaseous phases. This expertise has enabled a focus on both efficiency and sustainability, setting new standards in recycling technology. This paper discusses the key milestones and lessons learned over two decades of cemented carbide recycling, highlighting the progress made and the ongoing efforts to improve resource efficiency while minimising environmental impact. It provides a comprehensive overview of the journey and demonstrates the commitment to sustainable metallurgy.

Abstract
The traditional alkali-acid leaching process for treating waste hard alloys produces harmful solid tungsten leaching residues. This study proposes the reduction smelting of waste tungsten leaching residues using silicon and carbon as reductants, resulting in an alloy containing W, Ta, Nb, Fe, Co, Ni, Cu, and Ag, with a recovery rate of valuable metals exceeding 90%. In addition, this paper investigates the corrosion mechanisms of waste tungsten residues from different processes on graphite crucibles, magnesium oxide crucibles, and alumina crucibles. Suitable smelting processes and crucible materials for different types of tungsten residues are also proposed.This environmentally friendly approach promotes sustainable recycling of valuable metals in the tungsten industry.

Abstract
WC-Co cemented carbides are, from both technological and economical viewpoints, one of the most successful examples of effective use of multiphase composites for tribological and structural applications. The invention in 1923 of these materials, in practice usually referred to as hardmetals, not only revolutionized the machine-building and metalworking industries, but also paved the way for creating tool materials by means of microstructural design. In this regard, along the last 100 years development of hardmetals has been moving from early trial and error approaches, taking into consideration the expanding background of practical experience, into those based on fundamental understanding of microstructure-property-processing correlations linked to basic scientific research. Within this framework, this contribution aims to review how hardmetals excel to three highly-demanded attributes for engineering components – to deliver, versatility and to be reliable - on the basis of materials science principles. Regarding the former, it is shown to be linked to their capability for optimally performing by combining inter-dispersed composite nature with unbeatable interface adhesion (wettability), compromising hardness/toughness relationship and intrinsic liquid-phase sintering within their processing route. Considering versatility, it is sustained by the wide range of microstructures that they are able to exhibit, in terms of relative amount and physical dimensions of their constitutive phases. This is key for understanding the broad range of industrial applications where cemented carbides become a preeminent material choice. Moreover, from the perspective of microstructural assemblage and chemical nature of constitutive phases, sustainability/criticality considerations are addressed, as they are nowadays attracting widespread attention and triggering the search of lighthouses for developing alternative (hard phase / binder) ceramic-metal systems. Last but not least, the extremely high reliability associated with fracture toughness and damage tolerance of WC-Co cemented carbides is highlighted. In doing so, findings attained by the effective implementation of advanced small-scale testing and complementary characterization techniques are shown for illustrating and validating the unique mechanical properties of these composite materials. Within this context, the engineering value of reliability is appraised by showing how microstructure tailoring based on damage tolerance principles may enhance the performance of hardmetals when subjected to extremely demanding conditions, such as contact loads, exposure to corrosive media, thermal shock and/or mechanical fatigue.

Abstract
The first generation hardmetals with binders reinforced by hard W-Co-C nanoparticles obtained by a special heat-treatment technology and brand-named   as MasterGradeTM were implemented in industry about 20 years ago. Although they have significantly improved performance, conducting the heat-treatment is expensive and the nanoparticles are thermally unstable. Based on results of basic research it was established that small amounts of TaC added to WC-Co hardmetals form an oversaturated solid solution in cobalt when solidifying the liquid binder during cooling from sintering temperatures. This solid solution decomposes when further cooling in the solid state resulting in the formation of (Ta,W)C nanoprecipitates in the binder. The effectiveness of hardmetals with such a nanograin reinforced binder is similar to that of the first generation hardmetals in various applications, so we designated them as ‘the second-generation Master Grades’. Their production is more economical and consistent, which ensures the more sustainable manufacture, and the nanoprecipitates are stable at elevated temperatures. Structure, properties and applications of the novel hardmetals fabricated in industry on a large scale will be presented.

Abstract
Cemented carbides are key technological materials in metal cutting, mining and wear applications.  One main challenge that faces the cemented carbide industry is the sustainable sourcing, supply, use and recycling of the main components to produce them. A reason is that almost all components of cemented carbides are categorized in the European Union as critical or strategic raw materials (CRM) because of availability, sourcing or price, among others: W, Ti, Ta, Nb, Hf, V, Ru, and rare earths. Co is a particular case since studies have also shown potential risks for human health. In this work, examples for design of new cemented carbides to replace CRM are presented. The focus is on replacement of gamma-phase former elements Ta, Nb, Ti; and binder metal Co. The work covers production, characterization and examples of real applications in cutting tools. Economic and sustainability aspects are addressed to highlight the advantages of the new designed carbides covered in this work.

Abstract
Iron based binders for cemented carbides present an interesting alternative to the traditional cobalt binders. Of particular interest is the ability to tailor the macroscopic properties of the cemented carbide by changing the microstructure of the binder Cemented carbides can already be tailored by changing grain size or phase fractions to increase either hardness or toughness, but generally an increase in one of the properties will lead to an unwelcome decrease of the other. In this work a cemented carbide with an iron based binder is investigated with respect to the metastability of the austenite phase. Mechanical deformation is used to induce a phase transformation, which is identified by the use of electron diffraction. This type of phase transformation is utilised in high-strength steels as a way of increasing the toughness through the TRIP-effect (TRansformaiton Induced Plasticity), and if this could be utilised in cemented carbides it could present a way to increase the toughness without also reducing the hardness.

Abstract
Dense TiC-FeCrMo cermets have been sintered from powder mixtures in which Cr has been introduced either as Cr3C2 or prealloyed Fe-Cr powders. TEM has been used to determine the chemical composition of both ceramic grains and the binder phase after sintering. Microstructures of as-sintered materials include tempered martensite, bainite, retained austenite and several secondary carbides (mainly M7C3 and M23C6). Precipitation of M7C3 carbides after sintering is avoided by reducing Cr and C activities (i.e. using Fe-Cr prealloyed powders instead of Cr3C2). Phase transformations induced by subsequent thermal treatments have been investigated as a function of the austenitizing temperature for different cooling rates. Thermodynamic modelling has been used to define optimum austenitizing temperatures as a function of C and Cr contents. Mechanical properties are strongly affected by thermal treatment: 50% hardness reduction is obtained after annealing at temperatures ranging from 700 to 850ºC. TRS values above 1.5 GPa and hardness over 11 GPa are obtained with the adequate selection of chemical composition and thermal treatment.

Abstract
This work examines the use of Chemical Vapor Infiltration (CVI) technology for creating fiber coatings tailored for high-temperature applications. With the growing demand for advanced, fiber reinforced materials in aerospace, energy, biomedical, and nuclear field CVI offers a robust solution for enhancing the performance of continuous fiber-reinforced composites.

Bernex has developed a new CVI fibre coating machine for continuous processing of ceramic and carbon fiber tows and preforms, and has proven coating recipes of: Pyrolytic Carbon (PyC), Boron Nitride (BN), Silicon Carbide (SiC) or a combination of these in multilayer structures. 
The significance of suitable precursor selection, optimization of the process parameters for uniform coating deposition and good infiltration ratio, as well as an engineering of fiber-coating interfaces, will be discussed.
This work aims to provide insights into the capabilities of CVI technology in addressing the challenges posed by high-temperature environments, ultimately paving the path for the development of next-generation materials.

Abstract
Zirconium carbides and nitrides are typical transition metal compounds combining both metal and ceramic-like properties, although their bulk compounds still suffer from fragility and brittleness. Few studies have already highlighted signs of plasticity for zirconium compound at the small scale. The present research investigates plasticity of Zr(C,N) single crystals by various micromechanical testing methods such as nanoindentation, nano-scratch and micropillar compression. The sample was produced by hot pressing and sintering Zr(C,N) powder. The different testing methods showed a great ability of certain Zirconium carbonitride crystal orientation to deform plastically, similar to ductile metals while maintaining a high strength. Misorientation spread mapping by electron backscatter diffraction showed clustering and anisotropy according to crystal orientation. Nano-scratching demonstrates a low coefficient of friction and ductile chip debris which changes according to crystallographic orientation. Micropillar compression highlighted -according to crystal orientations - either brittle catastrophic failure is occurring or an extensive plastic deformation with a strain around 5% with an ultimate strength of 11 GPa which is an outstanding combination of strength and toughness.

Abstract
The performance of hard coatings is largely defined by their mechanical properties, such as Young’s modulus, hardness, and fracture characteristics like toughness and fracture stress. Here, a portfolio of advanced techniques for assessing these properties is presented, particularly focusing on high-resolution cross-sectional modulus and hardness mappings of chemically or microstructurally graded coatings. These experiments, in combination with correlative microscopy techniques, form the foundation for leveraging gradient concepts in high-throughput materials testing. Additionally, methods for the characterization of fracture toughness and stress are addressed, revealing crucial information about the damage and wear behavior of hard coatings. Concepts for testing interface adhesion, strength, and shear deformation under severe loads provide key insights into the in-operando behavior of hard coatings during cutting applications. The portfolio of micromechanical characterization techniques available within the Christian Doppler Laboratory for Sustainable Hard Coatings lays the groundwork for the development of the first generation of sustainable, eco-friendly, high-performance hard coatings for tooling applications.

Abstract
This work presents a data-driven approach to create efficient digital twins of industrial deposition processes, merging regression algorithms with special implementations of Natural Language Processing (NLPs), specifically the so-called sentence tranformers to derive efficient surrogate models. Polynomial Chaos Expansion (PCE) is implemented to derive a surrogate model which allows for accurate yet computationally efficient analyses. Furthermore, as a side-outcome of PCE, it is possible to perform sensitivity analysis using Sobol' indices to quantify the impact of process inputs in the different Chemical Vapor Deposition (CVD) production runs. The encoding of categorical variables, such as the shapes of cemented carbide inserts of cutting tools, using sentence tranformers, reflects the physical similarity of the product, allowing a more accurate representation. This is crucial for the sensitivity analyses performed and also enables feature importance analysis to identify the most critical process inputs. The study's methods align with experimental data and theory, aiding in process design and optimization while reducing the need for costly experiments. It highlights the potential of data-driven computational methods in prescribing optimal reactor configuration.

Abstract
The central role of hydrogen in the global energy transition underlines the urgency to develop robust material concepts for the hydrogen economy and infrastructure. Steel, known for its remarkable strength and toughness, is the most commonly used material in hydrogen technologies, but it is susceptible to hydrogen embrittlement (HE), a phenomenon that leads to degradation of the mechanical properties. Thus, the development of effective hydrogen permeation barriers (HPBs) is crucial to allow the safe application of steel in hydrogen technologies. Here, high entropy alloys (HEAs) are promising candidates due to their exceptional properties, including the sluggish diffusion effect. Thus, this study explored MoNbTaW-based HEA thin films with either Ti or Zr. The HPB efficiency was evaluated via in-situ electrochemical nanoindentation, applying a side charging setup, where especially the MoNbTaWZr films showed promising results, since no hardness increase could be observed for up to 160 min of charging time. This study provides the fundamental basis for further investigations to assess the full potential of HEA thin films for HPB applications.

Abstract
Nickel (Ni) and its alloys are commonly used as Cu/Sn bonding buffer layers in semiconductor 3D integration and display industries, and as hole transition layers in the perovskite industry. Since high-permeability Ni targets cannot be etched by magnetron sputtering, Ni layers are mostly prepared by electroplating. Compared with electroplating, magnetron sputtering generally provides better quality, higher purity, and higher density films. Therefore, to make Ni target more sputterable, some elements are added into nickel to adjust its properties. In this study, a small amount of molybdenum powder was added to nickel powder to prepare fine-grained, high-density NiMox sputtering targets by powder metallurgy. The sputtering targets contain a high weight percentage of Ni, the remainder of molybdenum (Mo), and unavoidable impurities. Ni-rich solid solutions can be detected by XRD measurements. We study the microstructure, magnetic permeability properties, and chemical properties of different NiMox alloys.

Abstract
The wetting behavior of liquids on various surfaces is crucial for many industrial and scientific applications. This study examines the wetting behavior of Galinstan, a liquid metal alloy, on surfaces with different coatings (metallic-, nitride-, or oxide- based) achieved through chemical or physical vapor deposition. Special attention is given to the surface structure, including porosity and roughness. In addition, laser engraving is used to create artificial homogeneous surface patterns. We systematically correlate the surface chemistry and structures by analyzing the contact angle and spreading dynamics of Galinstan on these surfaces.

Our findings reveal significant variations in wetting behavior, emphasizing the role of surface energy and its correlation with surface structure and chemistry. These insights enhance our understanding of surface engineering, enabling tailored advancements in material design and functionality for electronics, cooling systems, hydrodynamic bearings, and biomedical devices.

Abstract
In the past two decades, the field of materials science has seen the rise of “high entropy alloys” (HEAs), comprising a solid solution of at least five primary elements in near-equimolar composition.
The nitrides studied include (Al,Cr,Ti,V,W)N, (Al,Cr,Mo,V,W)N, (Al,Hf,Ti,V,W)N, (Al,Cr,Hf,Ti,V)N, and (Al,Cr,Hf,V,Zr)N, building on Density Functional Theory calculations. These materials exhibited delayed formation of the detrimental wurtzite AlN phase during annealing. Additionally, their oxynitride and silicon-alloyed nitride counterparts showed exceptional performance for specific compositions.
The materials were prepared using reactive DC magnetron sputtering. Characterization techniques included X-ray diffraction, scanning electron microscopy and nanoindentation.
The primary investigation focused on how the mechanical properties of the coatings changed during vacuum annealing for up to 50 hours. Notably, none of the samples displayed wurtzite phase formation.
While the Si-alloyed variants were softer as-deposited, the oxynitrides demonstrated higher hardness both before and after annealing. For (Al,Cr,Ti,V,W)N  both the oxynitride and the Si-alloyed nitride extended the lifetime at elevated temperatures
Cube-corner indentation indicated lower fracture toughness for the oxynitrides, whereas the silicon-alloyed variants exhibited values comparable to their Si-free counterparts.

Abstract
In many papers, coatings are grown on different substrates to evaluate specific attributes, such as (micro)structural characteristics, chemical composition and/or performance/properties (e.g. optical, mechanical, tribological, etc.). Typically, the collected information is compiled, and the ‘nature’ of a specific coating (and/or deposition process) is defined as the collection of attributes obtained from coatings deposited on different substrates under the same deposition conditions. However, that approach relies on the hypothesis that coatings grow ‘similarly enough’ on different substrates, at least when the deposition process is performed at the same time.
The objective of this work is to examine the validity of that hypothesis. To do so, we have explored the growth of Ti-Al-(Si)-N coatings on substrates of different nature (WC/Co, Si (100), Si (111), glass, and MgO) by transmission electron microscopy (TEM) and X-ray diffraction (XRD), which was used to evaluate the preferred orientation from Bragg-Brentano patterns and dedicated pole plots. We will show that, while monolayers show similar characteristics on different substrates, the growth of multilayers varies depending on the substrate employed.

Abstract
We discuss some experimental aspects of the Oliver and Pharr method that are often ignored but should be considered to obtain reliable results. We evaluated the mechanical properties of Ti-Al-Si-N coatings grown on Si (100) and WC-Co, which reveals specific challenges; thus, the reduction of data dispersion by properly polishing rough samples will be demonstrated, and the influence of size and glueing on Si substrates will be discussed. In addition, the fitting range of the unloading curve, as well as the depth range and age of the tip calibration area function, will be evaluated. Finally, it is verified that each substrate shows a different influence on each property. Thus, the variation of elastic modulus with depth is different if the substrate is stiffer than the coating or vice-versa. This indicates that the typical rule of ‘10% coating thickness’ is only valid for ‘local’ phenomena, such as hardness measurement; in contrast, elastic modulus should be evaluated near the substrate. A simple fitting function representing the stiffness transition from the coating to the substrate will be presented.

Abstract
In magnetron sputtering, particles are ejected from the target as atoms but can become ionized on their journey to the substrate, particularly in methods like Ionized Physical Vapor Deposition (IPVD) and High Power Impulse Magnetron Sputtering (HiPIMS). The Ionized Metal Flux Fraction (IMFF) in non-reactive sputtering of metallic targets is defined as the ratio of measured metal ions to the total of both metal ions and metal neutrals in the deposition flux. This study presents findings from IMFF measurements conducted in both laboratory and industrial settings, focusing on the sputtering of Ti, Al, and Cr targets. We will highlight four innovative strategies to maximize IMFF while ensuring a high deposition rate. Additionally, we will discuss how enhanced IMFF influences the properties of the resulting coatings.

Abstract
This study investigates the oxidation properties of group IV to VI transition metal carbides (TMCs), specifically titanium, zirconium, hafnium, tantalum and tungsten carbide, which are known for their exceptional thermal stability and mechanical strength, making them ideal for high-temperature applications in the aerospace, automotive and tooling industries. Despite their advantageous properties, TMCs face significant limitations due to their poor oxidation resistance. To address this challenge, we are employing a combinatorial PVD approach to investigate different alloying strategies – focusing on strong oxide formers such as Si and disilicides – leading to the formation of ternary and quaternary TMCs to improve their performance in high-temperature, oxygen-rich environments. Density Functional Theory calculations are used to establish a theoretical background for the phase formation of these novel material classes, which is subsequently validated by structural analysis. In a second step, the oxidation resistance of these materials is tested at temperatures up to 1500°C. The scale formations were analyzed using high-resolution characterization techniques. This comprehensive material screening approach aims to advance and promote the applicability of TMCs under extreme conditions.

Abstract
This study investigates the failure behavior of chemical vapor deposition (CVD) diamond-coated tools with various cemented carbide substrates during the machining of carbon fiber-reinforced polymer (CFRP) composites. The research aims to analyze the failure mechanisms of these tools and the impact of substrate materials on their performance. Cutting experiments were conducted under simulated industrial conditions, utilizing advanced characterization techniques such as scanning electron microscopy (SEM) and Raman analysis to examine the failed tools and identify failure modes. Results show that the tool with the S1 substrate, which includes TaC addition, exhibits superior wear resistance compared to the S2 substrate without TaC, especially in long-duration machining tasks. The primary failure modes identified are abrasive wear, adhesive wear, and coating delamination. These findings highlight that the bonding strength between the coating and substrate significantly influences tool durability. This research provides insights for optimizing tool design and selection, emphasizing substrate-coating compatibility to enhance machining efficiency and extend tool lifespan in industrial applications. Ultimately, this work contributes to improved cutting tool performance and reduced operational costs in CFRP machining.

Abstract
Metal-nitride coatings are widely employed in industrial applications due to their exceptional properties, such as high melting points, superior mechanical strength, and remarkable chemical stability. However, despite extensive research, limited data exists on their fracture toughness and wear resistance in cutting applications.
This study examines several commercially relevant monolithic, multilayer, and alloy-enhanced (Al,Ti)N and (Al,Cr)N coatings deposited via cathodic arc evaporation and sputtering techniques. The coatings were analysed in their as-deposited state and after annealing at 800 °C. Mechanical properties were evaluated with a particular focus on fracture toughness (assessed through micropillar splitting) and wear resistance (assessed through end milling and fly cutting experiments). Additionally, we examined the utility of semi-empirical criteria—specifically, H/E (elastic strain to failure) and H3/E2 (resistance to plastic deformation)—to predict fracture toughness and wear resistance. Our findings offer valuable insights into the predictive power of room-temperature test results for assessing the performance and durability of ceramic coatings in cutting applications.

Abstract
Oxide dispersion hardening (ODS) is a common approach to improve the high-temperature stability of metal thin films. The implementation of the ODS particles is usually realized by alternate or simultaneous deposition of the basic metallic thin film and the minor amount of ceramic material. This work presents a novel technique, in which the films are sputtered from a single Mo-La2O3 composite target. To evaluate the potential of this procedure, two Mo-La2O3 targets with different contents of implemented La2O3 of 0.7 or 2.1 weight-% were used for thin film deposition by magnetron sputtering. Films deposited from a pure Mo target served as reference. The film thickness was fixed to 100 nm and thermally oxidized Si was used as substrate material. A part of the samples was heat treated at 800 °C or 875 °C in high vacuum for 24 h. The analyses demonstrated that La species were successfully implemented in the thin films as well as their systematic influence on the film properties, such as morphology, phase formation and electrical resistivity.

Abstract
High-entropy alloy (HEA) thin films based on the equimolar AlCrNbTaTi system were deposited via magnetron sputtering. When synthesized at ambient temperature, the films exhibited an amorphous structure with an indentation hardness of 10.1 ± 0.3 GPa and a modulus of 195 ± 6 GPa. Increasing the substrate temperature enhanced crystallinity and mechanical properties, achieving values of 13.1 ± 0.9 GPa and 245 ± 8 GPa at 600 °C. Vacuum annealing at 850 °C further improved crystallinity but did not result in a single-phase solid-solution formation, unlike the behavior observed in sputtered AlCrNbTaTi-based carbide, nitride, and oxide films. The oxidation behavior of the metallic AlCrNbTaTi film during annealing in ambient air at temperatures up to 1300 °C was consistent with these materials, characterized by the preferential formation of a rutile-structured oxide phase, with minor contributions from other phases. Cross-sectional imaging revealed the development of porosity and blister formation in the oxide layer at elevated temperatures and longer annealing times, suggesting significant internal compressive stresses caused by volumetric expansion.

Abstract
Cutting tools are becoming smaller and more precise. It started with watchmaking and today’s drivers for this trend are medical and dental as well as the 3C industry. AI technology makes PCB tools for drilling computer boards a high-volume application for extremely small tools.

HiPIMS is the most suited coating technology for micro tools since it gives smooth coatings without any droplets, a dense and fine-grained morphology of the film together with low intrinsic stresses.

More knobs to turn – HiPIMS gives effective control over the plasma. The settings of the HiPIMS pulses allow us to tailor the energy precisely to micro tools. This avoids antenna effects and defects because of over-etching the fine geometry. Precision machining with micro tools requires super sharp cutting edges. The unique HiPIMS feature of synchronizing the pulses at the cathodes with the HiPIMS Bias supply is the key to actively managing the intrinsic stresses in the film.
HiPIMS with its unique combination of favorable properties opens new business opportunities in the growing market of precision and micro-machining.

Abstract
Machining of small precision components requires optimization of the entire process chain including cutting material, tool geometry, coating and operating conditions. A machining concept has been developed for the milling of stainless steel with micro-tools, taking into account various boundary conditions. The challenges were cutting edge preparation, tool coating and cutting technology for milling stainless steel 1.4441 with high accuracy.
The focus was on developing thin, wear and temperature resistant PVD coatings for micro-milling tools. The coatings were deposited using hybrid coating technology (combination of arc and sputtering process). The developed hybrid PVD coatings are characterized by high wear resistance and hardness at a coating thickness of max. 1 µm and a low roughness of Ra=0.005 µm.
In machining tests, tool parameters (cutting material, edge radius) and tool life were determined using line-shaped milling with micro tools d=0.5 mm. A new hybrid TiAlN-TiSiN coating shows the best results with up to 50% longer tool life, lower process forces and improved surface quality of machined components compared to reference coatings.

Abstract
Due to their high thermal and oxidation stability combined with a high hardness, TiSiN hard coatings are commonly used for severe cutting applications. The excellent properties are attributable to the nanocomposite structure: a nanocrystalline Ti(Si)N phase embedded in an amorphous SiNx tissue phase. To gain a deeper understanding of the nanostructure and elemental distribution, advanced characterization techniques such as atom probe tomography (APT) are crucial. In the case of TiSiN, however, peak overlaps of Si(2+) with N(+) at 14 and 15 Da and Si(+) with N2(+) at 28, 29 and 30 Da occur in the mass spectrum, which significantly reduces both, elemental accuracy and imaging precision of APT. Thus, within this study two approaches are presented to statistically correct the peak overlaps: (I) Peak decomposition based on natural isotopic abundancies and (II) peak deconvolution of the mass spectrum to improve the elemental accuracy. Furthermore, a spatially resolved decomposition is presented to increase the imaging accuracy of Si and N ions. The presented approaches enable unprecedented insights into the nanostructure of TiSiN.

Abstract
Chemical vapour deposition of polycrystalline α-Al2O3 protective coatings results in adverse tensile residual stresses. To negate this, compressive residual stresses are induced into the surface by post deposition wet blasting treatments. The development of a facile and efficient method using confocal Raman spectroscopy was undertaken to investigate the extent to which the compressive residual stress gradients develop. The residual stress gradients of (0001) textured as-deposited and wet blasted α-Al2O3 coatings were determined by the relative shift of the Raman peak from the stress free state at 417 cm-1. Confocal Raman spectroscopy allows for resolution in the submicron range, and within this study a lateral resolution of approximately 406 nm and depth resolution of about 200 nm was achieved. Stress-depth maps were produced affording detailed information on the stress state of the material within an area of 5 x 5 μm and a depth of 4 μm. The validity of this method was established by correlation of the stress gradients with synchrotron X-ray nanodiffraction experiments.

Abstract
Owing to their superior mechanical properties, TiSiN nanocomposite coatings are known as excellent protective layers for cutting tools. In the present study isotopic substitution of N is applied to investigate the nanostructure of TiSiN coatings with varying Si contents using atom probe tomography (APT). TiSiN coatings containing ~2, 5, and 10 at% Si were sputter deposited using 15N-enriched nitrogen. The APT results show Si segregation to grain boundaries for all investigated coatings, which is further corroborated by complementary performed high resolution scanning transmission electron microscopy investigations. Further, no Si-free regions could be observed by APT, evidencing that for all coatings Si is also incorporated into a Ti1-xSixN solid solution. The highest hardness, determined by nanoindentation, was obtained for the coating containing ~5 at% Si. This study demonstrates the feasibility and effectiveness of isotopic substitution of N to overcome the challenges related to distinguishing between Si and N peaks in the mass spectra of TiSiN synthesized with naturally abundant nitrogen. The presented methodology marks a significant step forward in the characterization and visualization of TiSiN nanocomposite coatings.

Abstract
High entropy nitrides are of great interest due to their structural stability and exceptional properties, now being explored for protective coatings. Here, the structural, mechanical and thermal properties of AlTiHfNbTaZrN coatings from medium to high entropy are investigated by ab initio calculations and experimental techniques. All coatings exhibit thermodynamic stability in a rock salt structure. The hard-yet-tough Al0.39Ti0.18(Me)0.43N and Al0.38Ti0.14(Me)0.48N high entropy coatings are attributed to the solid solution hardening and intensified lattice strain as well as more Ta- and Nb-inducing metallic bonds. Also a pronounced improvement in thermal stability is evidenced by phase and hardness evolution upon annealing, with peak hardness of ~36.8 GPa for Al0.39Ti0.18(Me)0.43N and ~37.9 GPa for Al0.38Ti0.14(Me)0.48N at 1100 °C, respectively. More substitution of Ti with Me, revealing stronger ionic bondings with nitrogen, offsets the negative effect of lattice expansion and results in an increased average diffusion energy for non-Al metal (Ti, Hf, Nb, Ta and Zr) atoms. Furthermore, greater strain energy between c-AlN and the parent nitride hinders the coherent precipitation of facilely diffused Al atoms.

Abstract
The development of wear-resistant hard coatings using physical vapor deposition (PVD) is an expensive and time-consuming process. Traditionally, the deposition process is developed and improved based on the operator’s experience, involving trial and error by systematically changing deposition parameters to achieve the desired coating properties. This contribution takes a different approach: Instead of relying solely on the operator’s experience, it employs machine learning algorithms, including active learning, to provide data-driven guidance for the selection of deposition parameters to achieve optimized coating hardness. For this purpose, a dataset containing deposition parameters and hardness values of PVD TiAlN-based hard coatings is used to initiate an iterative process based on active learning, where the model analyzes results and recommends the most promising deposition parameters for subsequent experiments. With each iteration, the model refines its predictions, reducing the number of trials needed and accelerating the development of coatings with increased hardness. This research aims to accelerate coating development by integrating data-driven methodologies, such as active learning, ensuring sustainable consumption of materials and energy.

Abstract
Chemical vapour deposition (CVD) coatings are widely applied to cemented carbide tools to enhance wear resistance and extend tool life. However, localised damage of the coating such as chipping and crater wear often dictates the performance, making it critical to understand the localized micromechanical failure of the coating. One of the important factors influencing failure is the grain boundary behaviour of the coating.

This study investigates the grain boundary strength of CVD titanium carbonitride (TiCN) coatings using a combined experimental and numerical approach. Microcantilever bending tests are conducted until failure, providing data for calibrating a finite element model. Input data for the grain behaviour, including the Young’s modulus and estimated yield strength, are obtained from nanoindentation tests. The grain boundary strength is evaluated through inverse calibration. The results offer insights for enhancing tool longevity.

Abstract
This research aims to examine the impact of the hard phase and binder phase in hardmetals, as well as their synergy effect on the microstructure at the film/substrate interface and the related comprehensive performance of PVD-coated hardmetal cutting tools. Three types of substrates were prepared, including conventional WC–Co-based alloys, a binder phase model alloy (Co-based alloy), and two hard phase model alloys (binderless WC-based alloy, bWC). The WC–Co-based alloys are characterized by varied WC grain sizes (0.4–1.2 μm) and Co contents (3–12 wt.%). The composition of the Co-based alloy is  85.1Co–9.2W–4.7Cr3C2–1.0VC, while the bWC alloys include WC–6Mo2C–0.68Cr3C2–0.37VC and WC–3.65TiC–2.45TaC–0.5Cr3C2–0.22VC. Using a DC magnetron sputtering technique, two AlTiN-based hard coatings were deposited on the above substrates: a single-layer AlTiN and a multilayer TiSiN/TiAlSiN/AlTiN coating. The resistance against cohesive failure strength (LC1), adhesion strength (LC2), friction and wear performance, as well as residual stress of the coatings were systematically studied, with in-depth discussion on the influencing mechanisms of the interface microstructures and properties.

Abstract
Ternary Al1-xTixN-PVD coatings on cemented carbide cutting tools have become industrial standard in metal machining. Despite the high hardness and chemical stability of such hard material coatings, increased wear often occurs during the machining of stainless steels. By adding selected transition metals such as Nb, Zr and Ta attempts are made to create superior quaternary coatings (Al1-x-yTixTMyN) with improved thermomechanical properties and corresponding wear resistance.
The influence of the individual doping elements on the significant properties, such as morphology and wear behaviour of the deposited PVD coating systems, will be discussed in more detail within this research using scanning electron microscope and milling tests on steel grade 1.4301.

Abstract
This work presents innovative approaches for specimen preparation for atom probe tomography (APT) and transmission electron microscopy (TEM), using femtosecond (fs)-laser processing, offering alternatives to conventional methods. By directly creating microtip arrays or half grids from the material to be studied, these methods eliminate the need for lift-out procedures and reduce reliance on expensive consumables like prefabricated microtip coupons or half grids. Exemplary workflows using TiN model coatings on Si and cemented carbide substrates, followed by APT and TEM analysis, including successful APT measurements in both voltage and laser-assisted modes, will be showcased. Fs-laser processed structures not only eliminate the weak point of welds (like e.g. Pt) between specimens and supports, but also streamline preparation, reduce process complexity, and increase throughput, with potential for automation. These versatile techniques can be applied to a wide range of materials, offering improved efficiency and reliability. The results illustrate how fs-laser processing has the potential to transform APT and TEM specimen preparation by simplifying workflows, enhancing precision, and reducing the use of consumables.

Abstract
Thermal stability and mechanical behaviour are crucial criteria for designing next-generation protective coatings. Here, the impact of oxygen on the thermal stability of metastable NaCl-type transitional metal aluminium nitride coatings is investigated. Coatings with either titanium or vanadium as a transitional metal are deposited utilising high power impulse magnetron sputtering at 450 °C. Effects of the oxygen content and the energy of ions bombarding the growing coatings are examined. The coatings are further vacuum annealed for 30 minutes up to 1300 °C, and the subsequent detection of the hexagonal phase marks the thermal stability limit. The formation of the hexagonal phase in the material system containing oxygen requires the mobility of both metal and non-metal species. The mobility is investigated by ab initio calculations utilising machine learning interatomic potential. It is shown that the thermal stability enhancement by oxygen incorporation is caused by the high energy required to form oxygen vacancies, which enable the mobility on the non-metal sublattice.

Abstract
Sustainable data storage is increasingly important for cloud providers, companies, and individuals. Most stored data is "cold", meaning it is rarely accessed or modified (e.g., photos, research results). To store this data, cloud providers rely on energy-intensive server farms using HDDs, which have limited capacity. To address the energy demands and storage limitations, new storage media are now the focus of research. By utilizing a certain coating-substrate combination, it is possible to write data into ceramic data carriers using a femtosecond laser. Within our research we analyzed different coating-substrate combinations regarding their mechanical properties and laser ablation characteristics and also tested them for their thermal stability, oxidation resistance, and corrosion resistance. The coatings investigated (Cr, CrN, Cr2O3, CrB2, (Al,Cr)N) were deposited on different substrates by magnetron sputtering using different chromium-based composite targets. The obtained results prove the exceptional stability and durability of such ceramic data storage media. Once written, storing the data is almost without any energy consumption and such ceramic data carriers would allow to save most of used energy for storing data.

Abstract
Low pressure CVD (LPCVD) AlTiN coating has emerged as an ideal material for cutting tools in the hard coating industry, owing to its high hardness and wear resistance, along with outstanding high - temperature oxidation resistance and anti-spalling performance. In this study, we discuss the microstructure and properties of CVD AlTiCNO coating deposited by low pressure thermal CVD in an industrial reactor.The microstructure, mechanical properties and the cutting performance of the films were characterized by Scanning Electron Microscope (SEM), X-Ray Diffraction(XRD),Energy Dispersive Spectrometer(EDS), High-Resolution Transmission Electron Microscope (HRTEM) and Electron Energy Loss Spectroscopy (EELS). The experimental results show that there is also a multi-periodic coating structure composed of alternating Al-rich layers and Ti-rich layers in the AlTiCNO coating, and there are periodic concentration changes of O, Al and Ti elements, and O element exists in the Al-rich layer. The nano-hardness of the AlTiCNO coating can reach 37.6GPa. The cutting experiment results show that the AlTiCNO coating has excellent performance in turning GH4169 and milling QT500.

Abstract
Thermoelectric materials have gained much attention in recent years due to their ability to directly interconvert electrical and thermal energy via the Seebeck/Peltier effect. The efficiency of this process is generally dependent on three parameters - the thermopower and the electrical and thermal conductivity - which are represented together in the dimensionless Figure of Merit ZT.
In 2019, Hinterleitner et al. managed to produce thin films of bcc-Fe2V0.8W0.2Al with an exceptional Seebeck coefficient, but the samples needed to be heat-treated for one week to crystallize from their amorphous state.
In this work, we present Fe2VAl-based full-Heusler thin films retaining their crystallinity during sputter deposition. By tuning various parameters, we managed to fabricate films in a bcc-structure on silicon. These films were analysed using XRD, EDX - confirming that the films are crystalline Heusler-phases with full disorder - and by measurement of transport data. Thermal conductivity of the films was derived from thermoreflectance and specific heat capacity.
The measurements suggest a low thermal conductivity and a moderate Seebeck coefficient, resulting in a commendable Figure of Merit.

Abstract
To improve the limited oxidation resistance of transition metal diboride (TMB) ceramics, alloying with Si and disilicides phases is effective by forming highly dense and protective SiO2 scales. The addition of Si, TaSi2, or MoSi2 to TiB2 drastically reduces the oxidation kinetics and has minor influences on the mechanical properties such as hardness. However, the fracture characteristics of these Si alloyed TMBs are rather unexplored.
In the present study, we aim to unravel the fracture resistance, particularly KIC, of these Si containing TMBs at elevated temperatures up to 850 °C applying in-situ micromechanical testing techniques. Therefore, a set of Ti-TM-Si-B2±z coatings was deposited by non-reactive DC magnetron sputtering using different composite targets TiB2, TiB2/TiSi2, TiB2/TaSi2 and TiB2/MoSi2. Compared to binary TiB2+z and the quaternary Ti-Ta-Si-B2±z, the Si and MoSi2 containing coatings showed a clear onset of plastic deformation at around 600 °C. We connect this to the precipitation of silicon-containing phases out of the as deposited solid solutions – studied by in-situ XRD and TEM investigations – highlighting the importance of materials testing at application relevant temperatures.

Abstract
The development of new products in the tooling industry strongly depends on innovations within material science and especially hard materials. This evolution started already in the 1970s when the first CVD-coatings were deposited on indexable hard metal inserts. Other developments involved the deposition of diamond and Alumina and the invention of the various PVD processes. PVD-AlTiN-coatings became the first alternative to Alumina. The advantages of ternary transition metal nitrides are commonly known as well as their limitations, since cubic AlN automatically changes into the hexagonal species when an Al-content of 78% is reached. To circumvent this problem the CVD technique was used. With a purely chemical process and a specially composed gas phase it is possible to further increase the Al-content up to 90% and still obtain mainly cubic phase., which further enhances the superb properties. In this contribution, results of these process variations shall be discussed on the bases of data from electron microscopy and X-ray diffraction in order to correlate structural properties with the performance of the particular coatings under special milling conditions.

Abstract
Transitional metal (TM) nitride coatings are widely used to improve performance of cutting tools. It is well known that adding aluminum to conventional TiN or CrN coatings is a simple and effective way to increase for example hardness and oxidation resistance as long as the cubic lattice structure is maintained. The introduction of cubic-phased AlTiN made by CVD some years ago excited academia and industry alike. Such highly metastable coating systems were thought to be possible by PVD at low temperature only. In fact, it sparked further efforts in arc and sputter deposition to find ways to also increase Al content above the critical elemental ratio of 2:1 in Al-TM-N where the soft hexagonal (AlN) phase would normally dominate. In this contribution, we are explaining efforts made by PVD and CVD to increase Al in AlTiN coatings with a focus on cutting tools. We are discussing the pros and cons of both PVD and CVD methods to deposit such highly metastable materials. We will conclude with an outlook on possible future applications of Al-TM-N protective coatings.

Abstract
Different MT-TiCNO coatings were deposited on iron sheets by moderate temperature chemical vapor deposition (MT-CVD). the high-temperature stability of the coatings protected by Ar and the high-temperature oxidation behavior in an oxidizing atmosphere were investigated using a synchronous thermal analyzer （STA）. The results show that the MT-TiCNO coating under Ar gas protection maintains the FCC structure after treatment at 1400 ° C, and the crystallization is more complete through atomic rearrangement and recrystallization. MT-TiCNO coatings have two mechanisms for high-temperature oxidation: 1. Below 600 ° C, the MT-TiCNO coating surface is oxidized to Anatase TiO2 with a conversion rate of approximately 8.9%. 2. Above 610 ℃, MT-TiCNO coating is oxidized to rutile TiO2. The oxidation reaction is limited by the conversion of Anatase TiO2 to rutile TiO2. The oxidation conversion rate of MT-TiCNO coating is different at different temperatures.

Abstract
A low sintering temperature high-entropy carbide (TiVNbCrMo)C was successfully fabricated at 1400 °C using solid-state vacuum sintering. The resulting high entropy carbide (HEC) exhibited a stable rock-salt FCC structure at room temperature. Variations in carbon content led to the formation of secondary carbides, which enhanced the mechanical properties of the HEC. Chromium carbide formation was observed at lower carbon content. The HEC displayed a homogeneous distribution of metals within its grain boundaries and achieved a maximum density of 99% at 1400°C, marking the lowest sintering temperature reported for this class of materials. The Vickers hardness was measured at 2400 HV10, with a fracture toughness of 6 MPa·m1/2.

Abstract
WC-Co hardmetal is prone to oxidation which limits its use in high-temperature applications. When WC-Co is exposed to an oxidizing environment at high temperatures, the volume expansion due to the formation of WO3 can cause the eventual disintegration of the material. In this study, chromium (Cr) was incorporated into the WC crystal to produce (W,Cr)C phase with an improved oxidation resistance. The formation of Cr2WO6 was shown to be critical to the reduction in the degradation of the material due to oxidation. The oxidation behavior of (W,Cr)C-Co hardmetal was evaluated against WC-Co hardmetal. Weight gain measurements showed an improvement in the oxidation resistance of (W,Cr)C-Co hardmetal. The microstructural features of (W,Cr)C-Co hardmetal were observed and its properties were measured.

Abstract
Given the problems associated with cobalt, the study of alternative binders for tungsten carbide is a priority. Iron-manganese binders have shown interesting results in terms of mechanical properties, although their microstructure contains eta-phase. Carbon doping (C-doping) of these composites was investigated in the scientific literature but yielded inconclusive results.
This study highlights C-doping applied to the binder. To this end, the milling process is adapted. A two-stage milling cycle is used. The first stage involves mixing Fe-Mn-C, with the aim of specifically doping the binder first. During the second cycle, the WC powder is mixed with the doped binder powder. The result of these cycles is a more homogeneous W-C-Fe-Mn powder. The milling parameters are optimized to obtain the finest possible powder mix.
Finally, the samples are sintered under conventional sintering and their mechanical and corrosion resistance properties are compared with those of WC-Co and undoped WC-FeMn composites.

Abstract
It is an ongoing strive to find alternative binders to cobalt due to its environmental and health impact. However, it is difficult to replace or limit the amount of cobalt without impacting material properties in a negative way. It is known that Fe-based cemented carbides present reduced hardness-toughness ratios compared to their Co-based counterparts, mainly due to the formation of brittle phases i.e. martensite, Fe-carbides etc. In this work we demonstrate how mechanical properties of cemented carbides containing Fe binders can be improved by careful alloy design. This is achieved by proper balance of alloying elements to produce cemented carbides with optimal content of metastable austenite phase in the binder. The design shows that it is possible to improve fracture toughness without compromising hardness of the material. The relationship between the relative fraction of metastable austenite in Fe-based binder (determined by X-ray diffraction) and its correlation to hardness/toughness ratios was studied for cemented carbides with varying grain sizes. Ways to stabilize retained austenite are proposed based on alloy and microstructure features design.

Abstract
Milling is a crucial step in the preparation of cemented carbides. It requires the homogeneous mixing of tungsten carbide with the metal binder without contamination of the powders by the grinding elements. Due to the high hardness of tungsten carbide powder and the high energy involved in the process, the grinding balls and bowls are usually subjected to high wear rate, which limits their use and thus enhances the production costs.
An alternative production route for cemented carbides is the deposition of the metallic binder onto the powder particles by a chemical process. Electroless plating has shown many advantages in the coating industry. It has thus been used for powder preparation by coating nickel on WC surface particles.
Ni-bonded tungsten carbides have been prepared in less than one hour including the bath preparation and the Ni plating itself. The paper deals with the optimization of the plating parameters to create cemented carbide powders suitable for the PM industry (5-20 wt.%).

Abstract
Hard metal, also known as cemented carbide, is a composite material widely utilized in various industrial applications due to its exceptional hardness and wear resistance. It primarily comprises tungsten carbide particles bonded by a metallic binder, typically cobalt. With tightening exposure limits for cobalt, it is crucial to monitor and manage potential exposure levels for workers. This study aims to simulate the dispersion of hard metal dust in a production environment and evaluate potential exposure levels for workers. The simulation was conducted using computational fluid dynamics (CFD) and atmospheric dispersion models to analyze dust particle behavior. Key fluid dynamic properties, including air and particle velocity, pressure, and dust dosage, were examined. The results demonstrate the spread of hard metal dust within the production facilities and the influence of fixed equipment, obstacles, and ventilation on dust dispersion patterns. Based on these findings, several mitigation strategies were proposed to control dust dispersion and reduce worker exposure.

Abstract
Artificial intelligence (AI) algorithms have been widely adopted in both academia and industry. In the context of tribological systems, abrasive wear is one of the main failure mechanisms in metal-hot forming tools, in which carbides significantly affect wear resistance. This study aims to develop an AI algorithm to predict the effect of carbides on the wear coefficient. In addition to wear, carbides are an essential phase acting as a thermal barrier. Three machine learning models were explored: Robust Linear Regression, Random Forests, and Artificial Neural Networks. The dataset was built from experimental and numerical results from multiple scratch tests on indefinite chill double pour (ICDP) cast iron. The tests were conducted at the microscale using the Bruker UMT-2 tribometer, while numerical modeling was carried out using Abaqus software. Simulating heterogeneous microstructures proved to be a significant challenge. The normal loads applied in the tests were 3, 5, and 10 N. Despite the limited dataset, Artificial Neural Networks presented lower RMSE, resulting in superior predictive performance for wear coefficient behavior.

Abstract
Cemented carbides, particularly tungsten carbide cobalt (WC-Co), represent a growing material flow with established recycling techniques, offering a viable alternative to primary raw materials in components and applications based on cemented carbides. However, the use of recycled feedstock in thermal sprayed coatings and its associated environmental impacts are less addressed in the field. This study aims to investigate the environmental impacts and potential benefits of applying zinc-process recycled powder materials in thermal spray processes compared to traditional primary raw materials. A life cycle assessment (LCA) was conducted for thermal spray coating methods, HVOF and HVAF operated with diverse fuels, employing recycled WC-Co as a material feedstock. The benefit of applying recycled feedstock is illustrated by comparing the environmental performance indicators, such as CO2 footprint and cumulative energy demand (CED), of recycled raw material against primary raw materials in the thermal spray process.

Abstract
The European Union has classified tungsten and cobalt as critical raw materials, emphasizing the necessity for the development of efficient recycling techniques for cemented carbides in order to ensure resource sustainability. The zinc process is a promising technique that enables direct reuse of recovered hard materials in the production of new ones. During this process, zinc diffuses into the cemented carbide matrix, forming intermetallic Co-Zn phases with the cobalt binder. As a result of their greater volume compared to the pure binder, these phases lead to a disruption of the compact carbide structure. Subsequently, zinc is extracted through vacuum distillation, leaving behind a porous intermediate product that is mechanically processed into a powder suitable for direct production of new hard materials. Despite the potential of this method, the formation mechanisms and properties of Co-Zn intermetallic phases remain insufficiently understood. This study aims to investigate these phases in detail, providing valuable insights to optimize the zinc process and improve the efficiency and quality of cemented carbide recycling.

Abstract
Cemented carbides with good mechanical properties and low or no prompt activation would be useful for neutron shielding applications. Thermo-Calc calculations and experiments were performed to determine the two- or three-phase regions of WC-Fe and WC-Fe-Cr3C2-VC cemented carbides. Phase composition was determined and confirmed by metallography analysis and XRD studies. Microstructures of cemented carbides consist of three phases (WC, ferrite and cementite). The influence of the Fe binder content, WC mean grain and carbon content on physical and mechanical properties of WC-Fe-Cr3C2-VC cemented carbides were investigated. With increasing the binder content, WC mean grain size and carbon content the mechanical properties such as density, hardness and transverse rupture strength decrease whereas the fracture toughness increases. Physical properties (coercivity and magnetic saturation) decrease with increasing WC mean grain size, carbon content and binder content. Fracture toughness greater than 8.0 MPam1/2, 100.0% density and relatively broad three phase window were found by employing extra-coarse WC and binders containing 5%Fe-0.30%Cr3C2-0.05%VC.

Abstract
This study examines the in-situ formation of carbide phases on Fe-based material via plasma transfer arc (PTA) cladding, using ZrO₂, TiO₂, and graphite powders. The feedstock powder comprises ZrO₂, TiO₂, graphite, and AISI 316L stainless steel. The powders were prepared with conventional ball milling during 72 hours. Hardfacings were created under controlled PTA  cladding conditions, with 0.7 mm/s torch velocity and 110 A current. Microstructural and compositional analyses were conducted using energy-dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). Vickers hardness was evaluated on cross-sections of each sample using a 5 kgf load and 10-second dwell time, and the specimens were preheated to 300ºC before cladding to support carbide phase formation. This research provides insights into the microstructure, hardness, and potential for carbide phase development using graphite, ZrO₂ and TiO₂ on Fe-based material. The research aims to contribute to the field of enhancing wear resistance in industrial applications of Fe-based materials.

Abstract
Co-sintering of various hardmetals allows tailoring material properties within a single component, and hence improving performance in applications requiring a balance of hardness and toughness. This study investigates the co-sintering of cemented carbides with varying gamma phase content, focusing on interface bonding and post sintering deformation. As expected, geometrical distortions after sintering were observed when differences in gamma phase content were larger. This issue was mitigated by pressing at the same contraction factor. Furthermore, shear tests revealed that interferences applied between materials being sinterfused affected local strength and ultimately the mechanical properties. The effect of binder migration was negligible, not affecting the bonding between grades. These results highlight the challenges of co-sintering dissimilar cemented carbides and the need for optimizing pressing parameters to obtain strong interfaces and ensure structural integrity of the component.

Abstract
Health and safety regulations are increasingly strict when it comes to Cobalt dust in hard metal manufacturing. Hard metal producers have used granulated Cobalt powders since the nineteen nineties to reduce Cobalt dust. However, the conventional granulation process uses compaction pressure for the Cobalt granules sometimes resulting in inhomogeneous microstructures and thus inferior tool performance such as TRS. This is becoming a challenge particularly for fine grain carbides for which lower milling times are applied to reduce damage to the WC grains and hence potential grain growth. Lower milling times also reduce energy consumption and improve the overall carbon footprint.
The recently developed soft granulated Cobalt powder is solving this problem as it is easy to disperse while it still meets the criteria of dust-free, free-flowing and non-flammable Cobalt powder. The granules are produced without compaction pressure avoiding hard Cobalt granules. Metallurgical values and microstructures will be shared to show the differences between conventional and soft granulated Cobalt powders in submicron carbide grades.

Abstract
Additive manufacturing of hard metals is gaining attention due to its ability to fabricate complex-shaped parts and innovative functional designs. Among the various methods, binder jetting stands out as one of the most promising technologies due to its low cost and rapid manufacturing process, producing parts that are free from stress and cracks, with isotropic properties. One of the principal challenges in this technology is the procurement of high-quality WC-Co raw materials, which must exhibit high bulk and tap density, optimal flowability, effective sintering activity, a homogeneous WC grain size, and an appropriate particle size distribution. This research presents a comparative evaluation of different powders (plasma spherodized powders, thermal spray powders and powder specifically designed for BJ), covering aspects from powder characterization to the evaluation of sintered components. Finally, the strengths and weaknesses of each powder are detailed.

Abstract
The transition to clean energy technologies to facilitate net zero demands new and novel materials.   Improved evaluation of the properties of these surfaces will enable design for increased performance. This work presents a technique combining measurements of contact resistance with mesoscale topographical measurement to enable on-machine in situ microstructural phase identification.
Mesoscale topographical measurement was conducted using NPL’s micro-tribometer. A conducting indenter was used allowing for measurement of electrical signals from the surface whilst measuring variation of indenter height and the frictional force.
The system was validated by scanning an electrically conducting boron-doped diamond indenter across a WC/Co material at low contact forces. The resistivity of the material at the point of contact was calculated showing clear differentiation between the matrix and binder phases of the material. This correlated spatially with the phases identified in SEM examination.
Further work will be carried out to relate the electrical properties with the microstructure and localised mechanical properties of the different phases in candidate materials giving an enhanced tool for materials development.

Abstract
In order to optimize the manufacturing processes of hardmetals in terms of product quality, costs and sustainability, knowledge about the reaction during debinding and sintering is necessary.
Using thermodilatometry, thermogravimetry and mass spectrometry, differential scanning analysis and laser flash analysis extruded hardmetal is examined as an example. The information about the mass change behavior during debinding and about the shrinkage behavior during sintering in dependence on heating rates can be used for kinetic analysis. The resulting kinetic models can be applied for shortening temperature-time-profiles of production processes in order to reduce energy consumption.
Thermophysical properties like temperature diffusivity, heat conductivity and heat capacity of hardmetals and important furnace materials like graphite used for boxes and trays were determined in dependence on temperature. With the help of these data calculation of energy consumption during the furnace run for hardmetal production is possible. Energy consumption can be simulated and optimized for different utilization levels of the furnace or different hardmetal products to be sintered.

Abstract
This study investigates the widening of the equilibrium carbon window in Ti(C,N)-based cermets by employing Co-free compositions. Expanding the C window is essential, as it promotes the reduction of the liquidus line, enhances the wettability of the metallic binder on the ceramic phase, and improves sintering behaviour. A CALculation of PHAse Diagrams (CALPHAD) approach using Thermo-Calc software has been utilised to assess this possibility.
The influence of various metallic alloying elements and secondary carbides on C solubility is examined. Specifically, the effects of metallic elements such as Ni, Fe, and Cr within the binder phase are assessed, alongside secondary carbides like WC and Mo2C. The objective is to clarify the relationships between composition and carbon behaviour, leading to the strategic selection of elements that can expand the C window. This, in turn, aims to improve the sintering and overall performance of the cermets. Experimental correlations will validate the thermodynamic predictions, providing deeper insights into the design of Co-free cermets with reduced supply risks and enhanced performance.

Abstract
High-pressure grinding rolls (HPGR) have expanded their applications from the cement industry to the metal ore industry due to their high efficiency. Traditional cemented car-bide studs face challenges such as corrosion, abrasion, and breakage, which are caused by high temperatures from friction between the rolls and materials, as well as improper humidity control. To improve the reliability of traditional studs, a new stud, GL1501, has been developed. This development was based on an analysis of the HPGR's comminution process and the stress states of the studs. By optimizing the addition of Cr3C2 and its distribution in the alloy structure, GL1501 significantly enhances the stud's resistance to corrosion and wear, thereby extending the service life of the rolls. The study's results show that the alloy with a 2.0% by weight addition of evenly distributed Cr3C2 exhibits superior corrosion resistance, with an average transverse rupture strength exceeding 3950 MPa and a compressive strength reaching 5650 MPa, 10% and 15% higher, respec-tively, than those of traditional studs. Furthermore, the wear rate is reduced by 50%.

Abstract
Tungsten carbide has applications as a wear-resistant material, mainly cemented carbides. Previous work has shown efforts to obtain functionally graded material (FGM) tools made of WC–Co and tool steel using Spark Plasma Sintering (SPS). In addition, it is important to model and control the sintering process. This work used 7264 data from the SPS device to predict the displacement during the sintering of FGM, which offers key advantages in modeling the process. Therefore, parameters could be adjusted in real time. Several machine learning models were tested, including Random Forest, Support Vector Machine, Decision Tree, Gradient Boosting, and Multilayer Perceptron. Data on time, temperature, current, voltage, pressure, displacement, displacement rate, and vacuum pressure are available. The correlation between the variables was studied. Cross-validation was performed to avoid overfitting the models, and the data set was divided into 80% training and 20% validation. The best-performing model was Random Forest, and temperature control offers advantages such as precision in SPS. Therefore, the manipulated variable is the current and the controlled variable is the temperature.

Abstract
Cemented carbide with different milling time was prepared by the traditional powder metallurgy process. The effect of milling time on the WC grain size, sphericity and mechanical properties was studied by means of metallography, SEM and EBSD. The results show that, with the increase of milling time, the grain size of WC and solid solution are continuously refined. Specifically, the larger-sized WC grain change from spherical-like shape to irregular polyhedral shape with straight boundary. With the increase of milling time, the sphericity of the WC grain becomes higher. The sphericity of WC grain is in a corresponding relationship with the proportion of small-sized WC grain. The more small-sized WC grain there is, the higher the average sphericity of the alloy. The average sphericity of small-sized WC is the largest, followed by that of medium-sized WC, and that of large-sized WC is the smallest. With the increase of milling time,  the vickers hardness is higher, the fracture toughness is lower, and the fatigue performance increases first and then decreases.

Abstract
Zn treatment process is considered a very efficient way of recycling hardmetal scrap in terms on energy consumption and GHG emissions. This work analyzes the effect of powder processing on the pressing and sintering behavior of a Zn-reclaimed submicron WC-10wt.%Co-0.5wt.Cr hardmetal grade. Deagglomeration is key for achieving a homogeneous distribution of pressing additives and an efficient removal of porosity during sintering. Optimization of the milling process requires detailed monitoring of powder particle size distributions and surface areas as a function of milling parameters (i.e. solids loading, rpm, time, etc.). Infrared spectroscopy has also been used to determine the evolution of carbon and oxygen contents in these materials. Impurities, associated to the Zn-reclaim process and/or the milling process, have been precisely measured by means of inductively coupled plasma optical emission spectroscopy. These powder parameters have been correlated with those obtained from dilatometric, calorimetric and thermo-gravimetric tests and compared with those a reference composition processed from virgin powders. Abnormal WC grain growth has been investigated by means of EBSD technique.

Abstract
Essential strength and limiting strength of transverse rupture strength (TRS) for ultrafine grained WC-Co based cemented carbides with three kind of grain size and four kind of composition were investigated. Essential strength estimated by relation between TRS values and the defect sizes increased by decreasing grain size of WC. However, the critical strength, i.e. the maximum strength independent of the size of the origin of fracture, was not necessarily increased. This suggest that the limiting strength determined by invisible defect near fracture origin based on matrices strength of the cemented carbide. It was found the limiting strength of cemented carbides increased slightly with decreasing carbon content of the specimen. The additive amount of grain growth inhibitor, especially vanadium carbide, also influenced limiting strength. It was considered that the matrix strength was determined not simply by the strength of the Co phase, but by strength of WC-Co based cemented carbides including strength of WC/Co and WC/WC interfaces and thermal stress occurred by difference of thermal expansion between WC and Co.

Abstract
This study explored the effects of spark plasma sintering (SPS), additions of TiC and TiC7N3 secondary hardening phases, and femtosecond laser surface modification (fs-LSM) on the energy consumption and machining performance of NbC-based and WC-based cutting inserts during face-milling of automotive grey cast iron (a-GCI). Adding TiC and TiC7N3 to NbC-12Ni (wt%) compositions refined the NbC grain size in SPS samples (⁓ 1.6 µm) compared to the LPS NbC-12Ni (wt%) (⁓ 4.6 µm) sample, enhancing hardness and wear resistance. Abrasion wear and impact shock resistance were further improved via fs-LSM, which created pyramid (P) and shark skin (S) micropatterns on the inserts’ surfaces. Face-milling trials were conducted at a cutting speed (Vc) of 200 m/min and a depth of cut (ap) of 0.1 mm. Among the NbC-based inserts, the SPS NbC-10TiC-12Ni (wt.%) blank (B) insert exhibited the lowest specific cutting energy (Uc) (19.02 J/mm3), followed by the SPS NbC-10TiC-12Ni (wt.%) P-LSM insert (22.91 J/mm3). Overall SPS, fs-LSM, and additions of TiC and TiC7N3 improved the machining performance of NbC-Ni inserts.

Abstract
The complete substitution of tungsten carbide (WC) and cobalt (Co) has gained prominence in recent years due to Co's classification as a carcinogen and the classification of Co and W as critical raw materials in the EU as well as the regulations of the U.S. National Toxicology Program. In this study, substitution of WC and Co with advanced Ni and Fe-based bonded NbC hardmetals for the metal processing in electric vehicle manufacturing applications is explored. The developed NbC-Ni/Fe based materials employ a Machining Property Led Tailored Design (MPLTD) approach. This reverse engineering strategy uses data from machining performance to guide the development of microstructural, mechanical and behavioural properties. Four advanced NbC-based hardmetals were produced, two with Ni-based binders and two with Fe-based binders, along with two reference materials for comparison (similar to SB40 - WC-Co based, NbC-12Ni). These materials were characterized using field emission scanning electron microscopy (FE-SEM), annular dark-field scanning transmission electron microscopy (ADF-STEM), Vickers hardness, fracture toughness, and elastic moduli. Cutting tool inserts were manufactured from the developed hardmetals, and there cutting edges were improved using femto-second laser surface modification. The inserts’ performance was evaluated through face milling tests on AZ31 automotive magnesium alloy, providing insights into their suitability for high-demand industrial applications.

Abstract
A poster contribution is offered to disseminate information about the AIM-NEXT project, funded by the European Union’s Horizon Europe program under the Marie Skłodowska-Curie Actions, dedicated to advancing European industry by educating 10 Doctoral candidates in sustainable material solutions for extreme engineering applications. This project focuses on accelerating the design and integration of hard materials using non-critical raw materials, effectively addressing economic and environmental challenges within the European Union. Through a comprehensive interdisciplinary, intersectoral, and international training program, AIM-NEXT collaborates with leading European universities and prominent industrial partners to deliver a robust educational experience. This consortium equips researchers with essential skills in material design, processing, characterization, and performance evaluation, contributing to critical industries including mining, manufacturing, and construction. The doctoral candidates will engage in cutting-edge research and training across diverse technical, industrial, and academic environments, complemented by mandatory secondments and network-wide events. By combining advanced technical skills, interdisciplinary research, and substantial industrial exposure, AIM-NEXT enhances candidate employability, addressing the growing need for skilled engineers in the European workforce and supporting the transition toward sustainable production.

Abstract
The European Union’s Green Deal encourages companies to reduce their greenhouse gas emissions. To achieve a reduction in indirect emissions, green supply chain management is essential, which includes understanding of the carbon footprint of purchased products. Life cycle assessment (LCA) and product carbon footprint (PCF) methodologies can be employed for this purpose. The complexity of evaluating these metrics increases with the diversity of raw materials, production processes, and product disposal or recycling.
This study focuses on calculating the PCF of a cemented carbide insert. Despite the limited variety of raw materials used in cemented carbides, the production process is complex. The number of production steps and the variety of manufacturing equipment involved complicate the calculation of greenhouse gases emitted. Each production step is analysed separately in this investigation, identifying potential sources of greenhouse gases.

Abstract
Compact spherical tokomaks offer advantages over conventional reactors, including higher magnetic field strengths, greater power densities, shorter build times, and reduced costs. However, their design presents challenges, particularly regarding the limited space for the central column shield, which is crucial for protecting superconducting magnets from neutron radiation and high temperatures. Therefore, materials with high shielding efficiency are essential.

Tungsten carbide (WC)-based cemented carbides are promising candidates due to their excellent properties: high neutron attenuation, high melting points (~2700 °C), and good thermal conductivity (70-180 Wm⁻¹K⁻¹). While extensively studied in cutting and drilling applications, there is limited literature on their mechanical properties concerning irradiation damage and operational temperatures in fusion reactors.

This study investigates this gap by conducting W self-ion irradiations on WC-FeCr samples at doses of 0.13, 1.3, and 13 dpa at room and elevated temperatures (100, 250, and 400 °C). The mechanical properties (modulus, hardness, toughness) were measured using nanoindentations and single cantilever bend tests, comparing irradiated and non-irradiated samples to assess the impact of irradiation damage.

Abstract
In this work, the circularity of cemented carbide with alternative binders has been investigated with respect to sintering of mechanical-chemical recycled cemented carbide. The cemented carbide in question is based on WC-gamma phase and Co-free binder. The focus of this investigation is on powder characterization of the different stages of the process chain and the evaluation of microstructure and the physical and mechanical properties of the obtained sintered parts (initial powder mixing- sintering - chemical recycling - mechanical recycling - mixing of the recycled powders – sintering). This work shows promising results and assesses the feasibility and challenges for circular use of alternative binders in cemented carbides.

Abstract
WC-Co hardmetals are used in a wide range of applications due to their excellent mechanical properties. Accordingly, the relationships between microstructure and composition and the resulting mechanical properties such as hardness have been studied extensively and are well understood. In comparison, the thermal conductivity of hardmetals has not been studied in similar detail although this property can be of importance during application processes, e.g. for thermal management during cutting. In this study the thermal conductivity of WC-Co hardmetals with WC grain sizes between 0.1 µm and 2.4 µm and binder contents between 5 and 20 wt% was studied between 20 °C and 1000 °C. The relationship between grain size, binder content and conductivity as well as the addition of grain growth inhibitors and their influence on the interfacial thermal resistance is discussed. A semi-empirical model including the influence of temperature is presented. Additionally, the thermal conductivity was simulated using a structurally detailed numerical modeling approach. Both approaches are well suited to predict the thermal conductivity of WC-Co hardmetals from WC grain size and Co content.

Abstract
Persistent Homology (PH) analysis has attracted attention in recent years as a method for quantitatively understanding microstructural features. PH analysis is a mathematical framework that uses the concept of homology in mathematics for data analysis, allowing the shape of the microstructures to be captured and quantified. This makes it possible to obtain topological features in a quantitative manner. Therefore, the purpose of this study is to apply PH analysis to obtain the topological features of the microstructure in Mo-TiC eutectic cermets and to clarify the relationship between the microstructural features and the mechanical properties. SEM-BSE images were obtained for various compositions of the Mo-TiC eutectic cermets, and PH analysis was performed to extract their microstructural features. The Vickers hardness of the Mo-TiC cermets was measured, and the relationship between the microstructural features obtained by the PH analysis and the hardness was rationalized. It was found that the importance of these topological features increased with the number of alloy compositions analyzed.

Abstract
The study on flux systems for carbon extraction in tungsten carbide (WC) under oxygen with induction heating offers valuable insights. Using iron (Fe) and copper (Cu) fluxes aids in carbon extraction results in by-products like copper tungstate (CuWO4) and iron tungstate (FeWO4), rather than tungsten oxide. This method is efficient, requiring less flux, making it more resource-efficient. In contrast, the LECOCEL® (W or W:Sn) and Fe system poses challenges due to the formation of low level of stable intermetallic carbides such as W3Fe3Cx, which resist decomposition at high temperatures, complicating complete carbon extraction. The process depends on the precise ratio of WC to flux and demands accurate weight measurements and regular system checks to ensure consistent carbon determination. Routine cleaning of the combustion tube is essential to prevent residue buildup that can hinder the performance of the induction coil and oxygen flow to the sample. The research highlights the importance of selecting the appropriate flux and maintaining strict process control to optimize carbon extraction efficiency.

Abstract
The formation of the microstructure and physical and mechanical properties of powder metal matrix composites based on cobalt, nickel and iron with a volume content of tungsten carbide particles of 33% as a result of their vacuum compaction at low temperatures under impact loading was studied. The structure and mechanical properties of metal and composite powder samples obtained by compaction at the same temperatures were compared. This allowed us to establish the influence of tungsten carbide particles and the quality of the Me/WC interphase boundaries on the bending strength and other properties of the composites. It was also found that at impact compaction temperatures of composites of 750 and 950 °C, the strength of the samples under three-point bending is 1400-1600 MPa and 1600-2000 MPa, respectively, where the higher values correspond to a composite with an iron matrix. Such composites, as well as composites with a higher or lower content of WC particles, can be used to obtain a high-strength matrix of diamond-containing materials intended for stone processing and cutting strong concrete.

Abstract
Cemented carbides are prime candidates for applications where strength is a critical design parameter. However, in hard and brittle-like materials this mechanical property is controlled by propagation of pre-existing defects, either intrinsic or induced during manufacturing or service. Regarding the latter, damage tolerance becomes a key aspect to consider; thus, introduction of 'controlled damage' provides valuable insights to assess mechanical integrity of cemented carbides. Within this context, the laser ablation technique, with its dimensional precision, holds great potential for shaping micronotches for evaluating fracture toughness. In this study, the residual flexural and fatigue strength on samples with laser-ablated micronotches - with geometry and size similar to intrinsic flaws - were measured. Advanced characterization techniques, including scanning electron microscopy, were used to analyze fracture surfaces. It allowed fracture toughness assessment based on the differences found in the fractographic appearance and dimensions of mirror, mist, and hackle regions between surfaces of broken specimens subjected to either monotonic or cyclic loading. The results are finally validated by direct comparison with toughness values measured using other testing methodologies.

Abstract
Increasing reporting and regulatory requirements, alongside higher expectations from investors and customers, call for comprehensive and transparent sustainability data. To meet these demands and address industry challenges, Sandvik Coromant is dedicated to developing calculation methods and industry standards for the life cycle management of metal-cutting tool manufacturing. This study aims to establish a framework for life cycle assessments (LCAs) and evaluate the environmental impact of Coromant’s offerings. System LCAs were conducted for selected product lines in Gimo, Sweden, with a method for scaling to other global plants, considering data quality and availability.

The results are based on three pillars: LCA methodology for metal-cutting tools, development of data reporting for specific use cases, and benchmarking and literature review of data integration solutions to enable automatic or semi-automatic reporting globally. A cradle-to-gate LCA reveals the environmental impact of specific inserts and tool holders produced in Sweden. The study identifies production process hotspots and includes sensitivity analysis.

Abstract
Carbide contiguity in hardmetals is the fraction of WC surface touching another WC grain. Electron backscatter diffraction (EBSD) is a promising method for contiguity measurement because it can quantitatively classify boundaries in a microstructure, but underestimates the Co binder fraction and overestimates carbide contiguity. The state-of-the-art method uses linear intercepts on a backscattered electron (BSE) image, a time-consuming manual operation.
We present full-field, automatic measurements of WC contiguity by combining quantitative EBSD maps with high spatial resolution BSE images using the ‘MTEX-TrueEBSD for WC Contiguity’ experimental workflow and analysis program. ‘TrueEBSD’ is a MATLAB tool for correcting spatial distortions in EBSD maps, which we have implemented in the open-source analysis toolbox MTEX. We also present a new grain boundary reconstruction algorithm which improves the measurement accuracy of boundary lengths (used to compute contiguity) by eliminating the unrealistic ‘staircase’ artefact typical in boundaries reconstructed from pixellated EBSD maps.
We demonstrate our approach on four examples (high and low Co volume fraction, large and small WC grain sizes) to span the range of typical hardmetal microstructures.

Abstract
A novel synthesis method, in-situ synthesis and densification, is proposed to simultaneously form a high entropy carbide (HEC) solid solution phase and a dual-phase HEC-nickel composite in a single-heating cycle. The metal oxides of Ti, V, Nb, Ta, Mo, W, and Ni were combined with varying concentrations of graphite to define the carbon window for two-phase ceramic-metal composites. Powder compacts were pressureless sintered under vacuum at 1420°C. The carbothermal reduction was monitored by interrupting the sintering cycle between 600-1400°C, while dilatometry and thermal analysis were performed to investigate the shrinkage, chemical reactions, mass loss, and eutectic formation temperature. Using nanometric oxides as starting materials increased the chemical reactivity, lowering the synthesis temperature to 1200°C for fcc-(Ti,V,Nb,Ta,Mo,W)C-HEC phase formation. Microstructural analysis revealed a considerably homogeneous distribution of constituent elements within the HEC-phase. High-speed nanoindentation was used to acquire mechanical property maps, confirming the in-situ formed HEC-phase homogeneity. Sub-stoichiometric HEC-Ni cermets exhibited a hardness ~1600 HV30 and toughness ~8 MPa.m1/2.

Abstract
Despite its excellent properties, namely high hardness, high toughness and high wear resistance, cemented carbides suffer from accelerated wear in some applications, especially in machining applications, being for this reason important to improve its tribological performance. Surface modification emerged in recent years as a promising method to enhance the tribological properties of materials, by altering the topography or physical properties of a material's surface to modify the tribological conditions and achieve specific functionalities. Specifically, surface texturing has been applied in various applications to create patterns, textures or structures on the material’s surface to enhance its performance by lowering friction and controlling wear, being laser surface texturing the technique consistently showing the most potential.
In this sense, this work evaluates the influence of different cross-hatched micropatterns features, fabricated by laser surface texturing of green stage pressed cemented carbide substrates (WC-10wt%Co), on its tribological performance through the realization of lubricated wear tests. The specific wear rate and coefficient of friction were evaluated and related with the micropatterns features.

Abstract
Numerous applications involve processing metallic and composites powders at elevated temperature. Temperature elevation can induce different mechanisms that will change the powder properties. The moisture content will usually decrease at elevated temperature, the oxidation at the surface of the particles will be modified and the stiffness of the particles can change. All these particle properties modifications will lead to a variation of the powder cohesiveness and subsequently will influence the flowability. Therefore, it is essential to evaluate the powder behavior at a temperature close to the one seen in the process in order to provide reliable predictions. In this study, we investigated the influence of temperature on the flowability and rheology of hard metals powders in a rotating drum geometry (Granudrum, Granutools). A cylindrical cell containing the powder rotates at different speeds while being maintained at the target temperature (from room to 250°C). The impact of the temperature elevation on the powder flowability has been quantified precisely. Therefore, the importance of taking into account the processing temperature for powder characterization is highlighted.

Abstract
Silicon nitride (Si3N4) based ceramics have a combination of room and high temperature mechanical, thermal and electric properties that render this family of materials suitable for advanced structural components in high-performance applications. These materials are usually densified under nitrogen atmospheres and need the addition of oxide sintering additives that facilitate the formation of an intergranular liquid phase, promoting densification at relatively low temperatures. In order to further increase the creep and oxidation resistance of these materials, critical for their use as cutting tools, Si and N can be partially replaced by Al and O, forming the so-called SiAlON ceramics with minimized volumes of glassy phase. This study presents results of pressed Si3N4 samples with various powder compositions, fully densified via pressureless sintering at 1750 °C. Different Si3N4-Al2O3-Y2O3 powder mixtures were prepared and uniaxially pressed at 1.5 and 2 tons. Furthermore, the influence of green density on the mechanical performance and microstructure of the final products was evaluated, providing valuable insights into optimizing Si3N4 based ceramics for practical applications.

Abstract
An interatomic potential suitable for large-scale molecular dynamics (MD) simulation of WC-Co hardmetals has been developed. After reviewing eight models for pure cobalt, the best was a 2015 Tersoff-type potential from Petisme et al. This potential reproduces the correct sign and magnitude of the hcp/fcc energy difference and was the only one to predict stacking fault energies similar to density-functional-theory (DFT).

The original Petisme/Tersoff potential also contained W and C parameters, and so we computed properties for various binary compounds: three phases of Co3W, Co7W6, Co3C, Co2C, WC and W2C. Several important relative energetics were incorrect in sign and magnitude, and so we computed a new DFT database using CASTEP and refitted the potential using GULP.  

Lastly, we used DFT to compute properties of three low-energy ternary Co-W-C structures from Materials Project. To fit these structures it was necessary to use the most general three-body formalism available within LAMMPS. The new potential is currently being applied in MD simulations of interfacial sliding and binder recrystallisation, and initial results are promising.

Abstract
Titanium alloys are critical for the aerospace sector in aerostructural and aero-engine applications due to their high strength to weight ratio, fatigue resistance and oxidation resistance.

However, their low thermal conductivity and high chemical reactivity make them difficult to machine. When turning titanium alloys WC-Co tools wear rapidly due to the diffusion of cobalt and carbon out of the substrate resulting in reduced integrity of the tool material. In the case of milling, the wear mechanisms critical to the tools degradation are less understood and need to be further investigated.  

In this work the initial stage of tool wear when milling Ti-6Al-4V is analysed. Differing tool grades, with varying cobalt contents are used to shoulder mill Ti-6Al-4V workpieces for periods of approximately 8 minutes. These inserts were then sectioned and examined on their flank face using SEM.  Adhered titanium on the tools surface was observed and investigated, providing insights into initial wear mechanisms in milling and the potential role of subsurface porosity in accelerating tool degradation.

Abstract
Cr3C2-based hardmetals are rarely studied and applied in exceptional cases only. However, compositions based on Cr3C2 are widely used for thermal spray coating solutions for wear protection at temperatures up to 900°C and in corrosive environments. In the last years, for coating deposition several WC-alloyed Cr3C2-based compositions appeared, aiming to improve room temperature properties, but also keeping the exceptional high-temperature properties. However, fundamental metallurgical knowledge of the interaction of Cr3C2 and WC is missing. Furthermore, also the potential as cutting materials has so far not been studied. Thus, the focus of this study was a systematic investigation of interaction of WC and Cr3C2 in sintered bodies prepared by Sinter-HIP. In total 13 binary carbide compositions with Ni as well as plain WC-Ni and Cr3C2-Ni samples were prepared, containing all a constant Ni content of 15 vol%. All samples were studied by XRD, FESEM and hardness measurement (HV10 and HV0.3). Significant microstructural and hardness changes depending on the composition were observed. No formation of new carbide phases (e.g. (W,Cr)2C, chromium-rich M7C3) was found.

Abstract
Spherical fusion tokamaks require advanced neutron shielding with high stopping power to protect the superconducting core from radiation damage. Tungsten carbide (WC) is a primary candidate shielding material, but its defect production and swelling under neutron bombardment are not well understood. Displacement damage in WC was simulated experimentally using tungsten ion irradiations and characterised with Grazing Incidence X-ray Diffraction (GIXRD), Atomic Force Microscopy and Transmission Electron Microscopy. GIXRD measurements showed an initial lattice expansion peaking at 0.13 displacements per atom (dpa). Higher irradiation doses led to reduced swelling (1.3 dpa) and eventual contraction (13 dpa). Maximum lattice swelling (at 0.13 dpa) decreased with increasing irradiation temperature, from 1.3% at 100 °C to 0.5% at 400 °C. Samples contained a minor fraction (<5 vol%) of W₂C phase, which showed overall expansion at all doses, unlike WC. Density Functional Theory calculations were performed to identify the defect types responsible for shrinkage. This study informs operating temperature and dose limits for safe shield operation.

Abstract
The interest in NbC-based cermets arises from their potential to replace commonly used WC-CoCr, reducing health risks associated with cobalt and addressing geopolitical concerns over tungsten supply, thereby enhancing safety and sustainability.This study aimed primarily to develop NbC-based compositions for application in surface engineering but uses P/M technology approaches for the pre-development. In this study NbC(N)-based cermets with 20 vol% Ni- and Fe-based binders are investigated. Six different binders are used: Ni, Ni20Cr, Fe22Cr, Fe33Ni, Fe33Ni33Cr and 316L. Cermets were sintered with a SinterHIP at 1350 to 1450 °C and 100 bar Ar pressure. Microstructural and mechanical characterization were carried out by using OLM, FE-SEM, Vickers hardness and fracture toughness measurements. Abrasion wear resistance was studied according to ASTM G65, dry sliding wear according to ASTM G99. Finest microstructures as well as high densities are achieved with FeCr, FeNiCr, and NiCr. Using NbCN instead of NbC yielded finer microtructures. NbC(N)-Fe22Cr reaches a hardness of  1110 (1141) HV10, while NbC-Ni20Cr has a fracture toughness of 10.2 MPam.

Abstract
cWC (cemented tungsten carbide) is a recent candidate radiation shielding material and one of the potential applications is at or near the plasma face inside a magnetic fusion reactor. Until recently there is little data on the effect of sputtering and ion bombardment on the mechanical properties of cWCs at elevated temperatures. Simultaneous He-Fe ion irradiation on cWC was performed for the first time under reactor-like temperatures. Beams of 8 MeV Fe ions and 2.5 MeV He ions were incident on cWC targets at 673K, 823K and 973K target temperatures. In this work, He-Fe ions simulate bombardment and sputtering at and near the plasma-facing surface of a fusion reactor. Microhardness, K1C, and in-situ EBSD tensile testing were performed to better understand the mechanical properties of cWC after irradiation.

Abstract
A new alloy class called Metallic Diamond (MD) is formulated from 6 to 9 different elements.. The alloy project employs traditional parameters used for high enthalpy alloys (HEA) besides the maximization of the chromium equivalent expression. In this approach, one may choose the elements with higher Cr equivalent coefficients for expanding the body centred cubic (bcc) field.  Three MD alloys compositions are presented: Cr3FeMoNbTaTiV, CrFe3MoNbTaTiV and AlCrFe3MoNbTiV.  The alloys were melted at a plasma furnace and cast into copper moulds under argon. XRD indexing has shown only 1 or 2 similar bcc phases, which was confirmed by SEM analysis. Annealing treatments of alloys up to 1300°C can even improve the hardness. Vickers hardness results show values from 950 to 1300 HV for as-cast alloys, reaching 2000 HV when thermochemically treated. Fracture toughness measurements range from 8 to 20 MPa.m1/2. The alloys can also be powdered and fabricated by powder metallurgy routes. MD alloys are promising in terms of applications where high hardness materials are required such as tools and grinding components.

Abstract
The properties of the magnetic cobalt (Co) binder in tungsten carbide (WC) are of relevance not only for the mechanical properties of the hard metal, but also for non-destructive quality control using measurements of the coercive field Hc. As Hc is widely used as an indirect probe for WC grain size estimation, a thorough understanding of the interplay between the magnetization reversal process in the Co binder and the WC grains is highly desirable. Micromagnetic simulations are a powerful tool to model magnetic materials on length scales which are relevant in real world applications. We present results from microstructure models of WC-Co, which were created using a toolchain consisting of the polycrystal generation software NEPER and the CAD platform SALOME (both Open Source). We modelled an increase in Co content by increasing the thickness of a grain boundary phase around the WC grains. We show, that our micromagnetic simulation results follow a similar trend as experimental Hc data obtained from real hard metal samples.

Abstract
In this work, the influence of gamma-phase carbides on the overall fatigue behaviour of two (fine- and medium-grained) hardmetal grades is studied. The investigation includes assessment of mechanical strength and fracture toughness, as well as fatigue life and cyclic-loading crack growth (FCG) behaviour using pristine and notched specimens, respectively. Fracture under monotonic loading and finite fatigue life behaviour are statistically correlated, allowing to estimate the FCG behaviour of natural flaws. It is then compared with crack growth kinetics experimentally measured on samples with through-thickness long cracks. The mechanical study is complemented with an in-depth qualitative and quantitative characterization of the crack-microstructure interaction (paths) evidenced during stable crack extension for both cemented carbides under consideration. Finally, a detailed fractographic inspection by means of scanning electron microscopy is performed to evaluate similitude of fracture and fatigue micromechanisms between natural / small and artificial /long cracks.

Abstract
Cemented carbides – also referred in practice as hardmetals - are first-choice materials for a wide range of industrial applications. Main reason behind it is their composite nature, yielding the possibility of adapting to property requirements by adjusting the ratio and dimensions of the hard ceramic particles and the soft metallic binder. In many of these applications, contact loading response of hardmetals becomes key for optimizing performance of tools and components. In this regard, competence between quasi-plastic and brittle behavior is given by the intrinsic compromise between hardness and toughness. This is not only expected to be dependent on microstructural assemblage but also on loading condition, e.g. static vs sliding. This study aims to assess the transition between yielding and fracture for different cemented carbides through axial indentation and scratch testing. In doing so, critical loads defining onset for irreversible deformation and cracking emergence are determined, and corresponding quasi-plastic and brittle failure mechanisms are documented by means of scanning electron microscopy inspection of both top- and cross-section surfaces of residual imprints and scratch tracks.

Abstract
WC-FeCr is a candidate for shielding in fusion reactors due to its outstanding neutron attenuation properties, in combination with low-activation characteristics. However, the binder composition for optimal densification and thermochemical stability has not yet been optimised, nor have the densification mechanisms been established. Here, a comprehensive study into the sintering mechanisms and binder wetting along WC grains is investigated using spark plasma sintering. The temperature, pressure, dwell time and binder composition are systematically varied, and resulting microstructures studied using X-ray diffraction, SEM and EBSD. The formation of a surface reaction layer between the WC grains and Cr is a critical mechanistic step to enable binder wetting. We map out limits for such efficient wetting in terms of binder content, composition, and sintering parameters. The materials’ thermophysical and mechanical properties were then assessed, including the fracture toughness and thermal conductivity; both critical to shield performance. The properties are systematically linked to the microstructural variables, including porosity, grain size, and binder content, and the data fit with available models and literature data.

Abstract
It is well known that the addition of TaC into Ti(C,N) cermets could improve its interrupted cutting and milling applications by retaining the hot hardness and thermal shock resistance. In this study, the effects of 3 and 10 wt% TaC or 3 and 6 wt% NbC addition on the microstructure, mechanical properties and oxidation resistance of Ti(C0.5N0.5) based cermets were investigated. The phase compositions and microstructures were studied by Thermo-Calc thermodynamic simulation, XRD, SEM and mechanical properties such as TRS, KIC and HV30 were measured. All cermet compositions were fully densified when sintered at 1450oC for 90 min. A TiCN core-rim structure was observed in the TaC and NbC containing cermets. The N-rich Ti(C,N) grains are partially replaced by C-rich (Ti,Ta/Nb,Mo,W)C grains with increasing TaC/NbC content. A similar HV30 of 1530 kg/mm2, KIC of 8.0 MPa m1/2 and a flexural strength of 2100 MPa were obtained. Both cermets exhibited a similar oxidation resistance at 700oC with an oxide layer consisting of nanometric and submicrometric particles, as well as residual cracks generated from some coarse grains.

Abstract
Cermets are widely utilized in various industrial applications, particularly for wear-resistant components in machinery and tooling. Recent research focuses on iron-bonded cermets to promote sustainability by reducing reliance on cobalt and nickel binders, as well as minimizing the use of tungsten carbide. Despite these advantages, iron-bonded cermets traditionally do not achieve the strength levels associated with conventional cemented carbides. This study investigates the effects of molybdenum (Mo), tungsten (W), and chromium (Cr) on the erosive and impact wear properties of iron-bonded Ti(C,N)-based cermets. The wear rates are determined, and a comprehensive analysis of the wear mechanism is supported by Scanning Electron Microscopy, XRD, and 3D profilometry. The results propose a new composition of iron-bonded Ti(C,N) based cermets that exhibit superior erosive and impact wear resistance compared to traditional cemented carbides, indicating their potential as a sustainable alternative in industrial applications. This research contributes valuable insights into the development of high-performance, environmentally friendly materials for demanding applications.

Abstract
Metal-Ceramic laminates have many potential applications ranging from armor and shielding to soft magnetics. The performance of these structures largely depends on the achievable individual layer thickness and the adhesion between the metal and ceramic layers. Especially the latter can pose a challenge. In this work we present a new approach to forming such laminates and analyze the structural integrity of the obtained material.
Laminate discs in which the thickness of each individual layer was controlled were produced by generating a structured powder compact in graphite dies using selective powder deposition, followed by precompacting the powder structure in a tabletop hydraulic press and sintering using Field Assisted Sintering Technology (Fast), also sometimes referred to as SPS. The laminate discs were subsequently cut into bars using a diamond saw. The bars were in turn analyzed via 3-point bending.
During bending detailed analysis of the fracture / failure modes was achieved by monitoring the electrical conductivity of the bars, acoustic response during the bending itself as well as Digital Image Correlation to follow crack formation and deflection.

Abstract
High-entropy carbides (HECs) are advanced materials recognized for their excellent mechanical properties and thermal stability at high temperatures. This study explores the synthesis of HECs using an oxide-based carbo-thermal reduction method, focusing on cost-effective compositions with reduced critical raw materials (CRM) content. By incorporating chromium and titanium in place of more expensive and less abundant elements like hafnium and tungsten, the researchers aim to lower costs and maintain performance. Chromium is selected for its ability to improve material properties and lower processing temperatures, while titanium is favored for its abundance, affordability, and desirable crystal structure. The synthesis involves ball milling metal oxides with carbon, heat treatment at 1773,15 Kelvin, and sintering by spark plasma, yielding a single-phase HEC structure. Microstructural analysis using scanning electron microscopy and energy-dispersive X-ray spectroscopy, as well as X-ray diffraction, confirms a uniform element distribution. Mechanical properties were evaluated through nanoindentation, demonstrating the material’s high performance. This study highlights the oxide route as an efficient method for producing HECs with reduced CRM dependence, offering a cost-effective solution for advanced material applications.

Abstract
The quaternary phase diagram of the W–C–H–O system at temperatures of 1000–2323 °C was investigated and promising ways of obtaining tungsten carbide with a minimum content of C, W, and W2C impurities were determined. The research was carried out by calculating the equilibria of chemical reactions in ternary systems C–H–O, C–W–H, C–W–O, O–W–H and plotting graphical dependences of the composition of the reaction products on temperature with the determination of quasi-binary sections for each system. This made it possible to triangulate ternary systems and depict tetrahedral elements of the quaternary system W-C-H-O, in which, along with WC, only stable gases CO and H2 are present. It has been established that all the many WC synthesis processes without C, W, W2C impurities can be reduced to six typical expressions of three-component reactions, when the ratios of the content of the initial components (WO3, C, H2, CH4, H2O, CO2) provide the composition of the reaction products, which corresponds to the WC–CO–H plane of the W–C–H–O quaternary system.

Abstract
For over 100 years, cemented carbides have been the class of predilection materials for manufacturing cutting tools.
Moreover, the high hardness of tungsten carbide makes the processing of carbide-cobalt mixtures long and difficult for milling tools.
To avoid this problem, we would merge the tungsten carburization with the sintering of the finished part in a single operation called “reactive sintering”. Tungsten carburization occurs at temperatures similar to the sintering of WC-Co mixtures, which would facilitate this operation.
The study was carried out by preparing tungsten-carbon-doped cobalt mixtures, followed by pressing and sintering at 1450°C for 60 minutes under vacuum.
Grinding was done in a Fritch planetary ball mill at a speed of 600 rpm, using WC-6Co bowls (80 ml capacity) and balls (10 mm diameter).
The transformation was complete: only tungsten carbide and cobalt could be detected in the composite parts. The mechanical properties are also interesting, with the hardness reaching 1800 Vickers units.

Abstract
This paper reviews the effects of different reinforcement methods on the properties of TiCN-based cermets. Firstly, the introduction of TiB₂ significantly improves the hardness and wear resistance of TiCN-based cermets; using spark plasma sintering (SPS) technology, cermets with 30 wt% TiB₂ exhibit excellent mechanical properties. Secondly, the decomposition of AlN increases the nitrogen content, further enhancing the hardness and wear resistance of Ti(C,N)-based cermets; experimental results show that cermets with 1 wt% AlN have the best performance. Additionally, the addition of SiC nanowhiskers significantly improves the hardness and flexural strength of TiCN-based cermets, with cermets containing 2.5 wt% SiC nanowhiskers showing the best performance. Finally, using CoCrNi medium-entropy alloy (MEA) as a binder metal significantly improves the properties of TiCN-based cermets, especially in terms of hardness and toughness at high temperatures. In summary, the introduction of different reinforcement methods significantly improves the overall performance of TiCN-based cermets, providing new insights for their application in high-performance materials.

Abstract
The industries of intelligent connected vehicles, high-definition security, unmanned aerial vehicle, premium phone, AR/VR, and ultra-high pressure diamond synthesis are developing rapidly, which puts higher demands on the performance of cobalt free and low cobalt hard alloy materials. This report provides an overview of the research progress in equipment application, mechanism exploration, and new material development in Spark plasma Sintering (SPS) technology in China over the past two decades. The research progress and applications of cobalt free/ low cobalt cemented carbide, new bonding phases (cobalt based alloys and cobalt based high entropy alloys), and special cemented carbide are introduced in depth, and the future research focus and development trend in this field are also introduced.

Abstract
We have simulated de micromechanical residual stresses generated in two different cemented carbides with nickel binders, namely Ni-Co and Ni-Mo, by finite element modelling with meshes obtained from realistic microstructures adquired by tomographic reconstructions of Focused Ion Beam sequential images.
Strain measurements are obtained by neutron diffraction measurements under different temperatues (room, 500ºC and 600ºC) and under different compression loads. In addition, micropillars compression of the same materials are performed under the same temperatures in order to measure the micromechanical performance
Results show a good correlation between numerical modelling and experimental measurements, with a strong dependence of the local stress state with the microstructure.

Abstract
Due to the difference in thermal expansion coefficients between the coating and the substrate, residual thermal stresses are inevitably formed during the cooling process at the end of the coating, and cracks are more likely to develop in the places where these stresses are concentrated in the course of actual use. It is common to form a gradient toughness zone depleted of hard cubic phase on the surface of the substrate to prevent crack propagation. In this manuscript, the effects of gradient layer thickness and compositional variations on the residual thermal stress distribution and mechanical behavior of the substrate under external forces are investigated using microscopic image modeling. The results show that the cracks tend to start sprouting at the place where the Co layer between WC and WC is thinner and expand along the Co phase. Under the same external force, the existence of the gradient layer can effectively prevent the crack extension.

Abstract
Cermets, Ti-hard-phase based composite materials, offer a promising alternative to traditional cemented carbides, WC-hard-phase based composite materials, for metal cutting operations.
This study investigates the effect of different Ti raw materials and binder types on the processability and properties of cermet materials. Thermogravimetric and differential thermal analysis (TGA-DTA) were used on powder mixtures to understand the interactions between various Ti raw materials (TiC, TiN, TiCxNy) with a Co-based binder. These analyses were then followed by / complemented with  scanning electron microscopy (SEM) pictures of sintered materials and hardness measurements to assess their effects on the microstructures and mechanical properties.
Results from TGA-DTA for the different raw material highlighted a similar behavior between TiC and TiCxNy during the heating step whereas the behavior of the TiCxNy during  cooling was like TiN based material. This can be explained by the dissolution of nitrogen during the liquid phase sintering at the expense of carbon.
Comparison between Co and Ni binder cermet revealed that Ni binder promotes nitrogen outgassing during sintering. This phenomenon could be associated to some lower solubility of nitrogen in Ni binder and/or higher solubility of Ti.
Among the material studied, TiCxNy based cermets showed a rounded cermet like microstructure and the best mechanical properties.
Co binder cermet presented a higher hardness and finer microstructure than Ni binder cermet, which is likely due to the higher nitrogen solubility in Co binder.

Abstract
The study employs two cobalt carbonate forms to produce cobalt powder via hydrogen reduction, analyzing its properties using various instruments. The results show that the main factors affecting the tap density of cobalt powder are the particle size, morphology, and particle size distribution of the cobalt powder. Further analysis suggests that the tap density of cobalt powder essentially depends on the amount of internal voids in the powder accumulation state. In the case of cobalt powder with similar morphology, the Fisher particle size of 1.53 μm and 3.33 μm corresponds to tap densities of 1.46 g/cm³ and 2.44 g/cm³, respectively. Cobalt powder with short branch-like morphology and nearly spherical morphology prepared under the same reduction process correspond to tap densities of 1.46 g/cm³ and 1.67 g/cm³, respectively. Therefore, in the production of cobalt powder, the tap density of cobalt powder can be adjusted by controlling the preparation process of cobalt powder.

Abstract
Sandvik’s top hammer PowerCarbide® grade SH70 now combines high material efficiency with top performance. In close collaboration with Wolfram Bergbau und Hütten AG PRZ (zinc process recycled) raw material has been produced and used for powder production. In this “greener” version of SH70, 50% intake of PRZ-raw material combined with chemically recycled WC from Wolfram, resulted in total 75% recycled material content. The original SH70 grade powder has been already produced using high amount of chemically recycled raw materials to lower the environmental impacts, but the high PRZ intake further cuts the CO2 emissions by about 20%. Additionally, using PRZ material allows for nearly 100% direct reuse of the cobalt binder and herein reached 86.6 % direct reused cobalt. Premium cemented carbide quality and manufacturing specifications are maintained, and the carbide properties have been verified in lab wear tests and mechanical property tests as hardness, fracture toughness, tensile strength and compressive strength. Several field tests in mines and at construction sites have validated equal or slightly better performance of the “greener” version of SH70 carbide.

Abstract
Microstructures and properties of WC-Mo-Co cemented carbides (alloys) were investigated in detail. First, coarse-grained alloys (dWC=75-150μm) were fabricated, and the composition and hardness of the Co binder phase were examined. It was found that the addition of Mo increased the amount of Mo in the Co binder phase and increased the hardness of the Co binder phase. Next,  normal-grained alloys (dWC=3.5μm) were prepared and their microstructure, hardness and toughness were examined. The addition of Mo inhibited the grain growth of WC, and WC tended to take on a spherical shape. Mechanical properties are also discussed.

Abstract
Ceramic based hard materials, such as hardmetals and cermets, are produced through powder metallurgy, usually requiring the use of temperatures higher than 1400ºC and application of pressure through Hot Pressing, Hot Isostatic Pressing, or SinterHIP to fully densify. The development of alternative sintering techniques in the last decades has opened the possibility of producing such materials with a much lower energy input and towards the needed decarbonization route. One of such techniques is Flash Sintering (FS) – in the Electric Current Assisted/Activated Sintering (ECAS) group – which takes advantage of an electric field that is forced to cross through the sample, in a phenomenon known as Flash event. However, this technique is dependent on intrinsic material´s properties, namely the electrical conductivity, since Joule effect will play a crucial role in generating heat. In this work, the electrical conductivity of several materials (as TiCN, Al2O3, WC, B4C and cBN) was determined at different temperatures. These data were used to simulate, with COMSOL software, the heat generated by Joule effect and the possibility to densify by FS.

Abstract
Cemented Tungsten Carbide (cWC) is a radiation shielding candidate material for nuclear fusion reactors due its high density, ease of manufacture and excellent mechanical properties.
Sample irradiation consisted of 1.5 MeV protons at 410 K and at 823 K and 60Co gamma irradiation at 293 K and 77 K. Transmission Electron Microscopy (TEM) along with Wavelength Dispersive Spectroscopy (WDS) was utilized to understand irradiation response of WC and binder phase.

This detailed TEM analysis of control and irradiated WC phase (hcp) of cWCs, behaviour and preferred orientation of dislocations (line) and loops were investigated at various zone axes such as [100], [010], [001], [110], [120], [1 ̅1 ̅0], and [1 ̅01 ̅] with bright field 2-beam (BF) and weak beam dark field (WFDF) imaging. Edge-on and sharp dislocations line and loops were observed to be most visible in given conditions at [110], [120], and [1 ̅1 ̅0]. 823 K control and irradiated sample have shown very interesting dislocation behaviour as compared any other samples in this work, 410K samples being the most damaged samples.

Abstract
Cemented carbide is a tooling material, valued for its exceptional hardness and wear resistance. This study investigates the effect of annealing on the microstructural evolution of WC-Co cemented carbides containing varying amounts of chromium (Cr) as a grain growth inhibitor (GGI). Samples with different Cr weight percentages were annealed in a vacuum furnace at temperatures between 600°C and 1100°C. Annealing primarily affects microstructure through grain growth, however, it can also alter the grain boundary populations. To study this, Electron Backscatter Diffraction (EBSD) was used to characterize grain morphology, while stereological methods quantified the prevalence of low-energy, high-frequency grain boundaries. The area fractions of specific grain boundary types were statistically determined. This study tracks the evolution of 5-parameter grain boundary character in WC-Co during grain growth. Initial results reveal that annealing, along with promoting grain growth, also leads to an increase in the area fraction of Σ2 twist grain boundaries from 0.8% to 2%. These findings provide insight into optimizing the mechanical properties of WC-Co composites through controlled thermal treatments.

Abstract
This work studied the effect of the WC/Co ratio on the corrosion resistance of WC-Co hardmetals. Samples were produced with 1.3 µm average sized WC particles and increasing amounts of Co binder: 3.5, 5, 13, 25 and 50 wt%. The corrosion of the samples was investigated in aerated aqueous 0.5 M NaCl during one week, using electrochemical techniques such as open circuit potential (OCP), potentiodynamic polarisation curves and electrochemical impedance spectroscopy (EIS). The corrosion potential decreased with the increase in Co content. The corrosion rate was higher in the middle range of Co content, but when only the binder fraction area was considered the corrosion current density was higher for samples with less cobalt.

Abstract
Low-activation cemented tungsten carbides (cWCs) are recent candidates for compact radiation shielding in compact tokamaks and while there has been considerable advances in evaluating cWCs in a nuclear context experimentally and in silico, significant gaps remain. Fusion power plants will be expected to reliably operate for years at a time and it is critical that any shielding materials is stable and does not have any significant changes in properties over time during a duty cycle.
The first time-temperature-transformation (TTT) study of low-activation FeCr-cWC samples at reactor relevant temperatures is presented in this work. FeCr-cWCs with binder contents of 8wt% and 6wt% with target WC grainsize of 4 micron and 2 microns were held at 400C, 550C and 700C at dwell times between 8h to 176h and cumulative time up to 296h. Samples were characterized prior and post TTT by Vickers hardness, SEM and EBSD to investigate grainsize and phase presence, alongside differences between surface and subsurface properties in TTT samples. This work is the first part of a series of longer-term TTT studies.

Abstract
Hardmetal tools must withstand severe wear and fatigue stresses for long periods in most areas of application. Despite the exceptional combination of properties of conventional hardmetals, corrosion resistance is also often a design concern.
Hardmetals with Ni-based binders are used industrially as alternatives for WC-Co composites in wear and corrosion applications. The use of these alternative binders is supported by the growing interest and substantial characterization reported in the scientific literature. In high binder content hardmetals (> 20 wt.%), used in metal forming and cutting applications, the potential of alternative binder elements has been less explored.
In this work, the sliding wear resistance of hardmetals with 27 wt.% of various binders, including NiCrMo and NiCrAl, was evaluated and compared with industrial Co-based compositions, when in contact with alumina and steel 6 mm balls, following the ASTM G133 standard. Additionally, the corrosion resistance of these compositions was studied with electrochemical tests, such as open circuit potential, cyclic voltammetry and impedance spectroscopy, in neutral and acidic saline solutions.

Abstract
A novel alumina-assisted treatment process was proposed to prepare pre-alloyed WC-Co feedstock powders for thermal spraying applications. In as-sprayed coatings by the high velocity oxy-fuel spraying process, the decarburization phenomenon common in previous studies was almost eliminated, and a unique binder structure with nanocrystalline and amorphous Co co-existing was obtained. The wear and corrosion resistance of the developed WC-based coatings were 3-10 times higher than those prepared from conventional powders. Instead of plastic deformation, interface fracture and micro-cutting that mainly occurred in conventional coatings, fracture of WC grains and subsequent oxidation dominated wear failure of the new coatings owing to the significantly strengthened nanocrystalline Co binder and phase interfaces. On the other hand, the pre-alloying treatment resulted in formation of Cr-containing nano-precipitates at the ceramic/metal interfaces in the WC-CoCr coating. The driving force for micro-galvanic corrosion reactions between carbides and metallic binder was thus reduced. The developed powder pre-alloying technique, and the wear- and corrosion-resistant mechanisms of WC-based coatings can be applied to the microstructural control and performance enhancement of other cermet materials.

Abstract
High-entropy ceramics, such as high-entropy carbides (HECs), are innovative materials known for their enhanced mechanical properties compared to mono, dual, and ternary carbide counterparts. The high-entropy phenomenon also improves their chemical and thermal stability. HECs have shown promising potential as the hard ceramic phase in hardmetals. In this study, HEC-based hardmetals, prepared by different methods, were subjected to erosive wear at temperatures up to 700 °C to evaluate their stability and wear resistance under high-temperature (HT) conditions. Conventional hardmetals and cermets were tested as reference materials. The volumetric wear rate was measured, and worn surfaces were analyzed using X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS). These techniques were employed to investigate oxide layer formation and wear mechanisms during high-temperature wear.

Abstract
In this work, the temperature and stress distributions within rotating targets for ball bearing and liquid metal bearing X-ray tubes were analyzed on the basis of thermo-mechanic simulations by the finite element method. Liquid metal bearing, which has superior heat dissipation capabilities comparing to ball bearing, introduces significantly different temperature gradients in the rotating targets. Our studies revealed that the stresses in targets of a liquid metal bearing X-ray tube exceeded the yield strength of the molybdenum alloy, while the stresses for a ball bearing X-ray tube were below the limit under the same operating conditions. By adjusting the spinning speed of the target and the thermal resistance between the target and the bearing, the target in a liquid metal bearing X-ray tube could be subjected to a higher thermal load.

Abstract
ABSTRACT
Activated sintering of tungsten is generally induced by the addition of small amounts of group VIII elements, especially in the low temperature range of 1273–1473 K. The mechanism has been recognized to be correlated with the enhanced W diffusion rate along the segregated grain boundaries (GBs) due to the high solubility of W in the additive metal. Although these GBs play an important role in the activated sintering, the exact mechanism is still unclear. This is because most interpretations have been based only on sintering kinetics without a fundamental understanding of GB properties including structure, thermodynamics, and atomic diffusion. This overview focuses on the interpretation of discontinuous GB diffusion behavior of sintered tungsten in terms of potential GB phase transitions of W in the temperature range of activated sintering. Using the hints provided by GB diffusion measurements, a clear understanding of the underlying GB phase transitions is expected to bring about a breakthrough in interpreting the exact mechanism of low temperature activated sintering of W powders.
Keywords: Activated sintering; GB diffusion; Sintered tungsten; GB phase transition

Abstract
Despite the fact, that refractory metals are a quite challenging material, they have become very attractive for additive technologies. Although it is extremely difficult to develop perfect prints, there is a constant chase and demand on the market for materials developed in a way that allows to obtain elements with the desired properties. One of the proposals is to modify the composition by adding rhenium (the so-called “rhenium effect”). Although the problem with printability of such materials has been known for years, still there is little detailed information in the literature about materials such as W-Re and Mo-Re intended for additive manufacturing. The aim if this work was to characterize with different techniques W-Re and Mo-Re powders for LPBF technology. As part of the research, a wide microstructural characterization was carried out. The characterization was carried out using advanced techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and nanohardness testing. This combination of analysis techniques provided a multi-scale understanding of the microstructural evolution and elemental distribution within the powders.

Abstract
A type of polyoxymethylene (POM)-based binder has been developed for tungsten heavy alloys (WHAs) powder to form a feedstock similar to that used in metal injection molding (MIM). The feedstock is then extruded to fabricate the filaments, which is suitable for the common fused deposition modeling (FDM) or fused filament fabrication (FFF) 3D printing. The as-printed parts are subsequently catalytic debinded, sintered and further heat-treated via the traditional powder metallurgy route. An 93W-Ni-Fe alloy has been produced using this binder-assisted extrusion additive manufacturing (BAEAM) process. The resultant parts exhibited an overall relative density greater than 98%, an ultimate tensile strength exceeding 900 MPa, and elongation greater than 20%. The BAEAM process shows promise for fabricating WHAs components with tailored geometries for applications such as radiation shielding, warhead and balancing weights.

Abstract
The mechanical properties of additively manufactured molybdenum and tungsten components are affected by O contamination that can occur during powder storage. Oxidation of powder surfaces leads to oxide formation and grain boundary segregation at the end of solidification in powder bed fusion processes.
The effect of storage environments with varying atmosphere - air-conditioned room and two different inert gas conditions - on the humidity and O content of pure Mo, W and Mo-0.45 wt.% C powders over a one-year period is compared. The O content and the humidity level were measured by carrier hot gas extraction and Karl Fischer titration, respectively.
The results reveal that molybdenum exhibited a significant 107 % increase in O content in air-conditioned laboratory storage conditions, indicating low-temperature oxidation driven by humidity exposure. In contrast, Mo-0.45 wt.% C showed only a 16 % increase, and tungsten exhibited moderate oxidation of 52 %, in the same conditions. All powders did not show increased humidity or O content when stored in the inert gas environments.

Abstract
The Search for Hidden Particles (SHiP) experiment will investigate light, feebly interacting (slower decays) particles, see Fig 1. These particles are only theoretically predicted and include dark photons, axions and heavy neutral leptons. Ordinary matter, which is well described in the standard model, only makes up around 5% of the known universe. To create these low mass, feebly interacting particles, SHiP will use a high-energy (400 GeV) and high-power (350kW average beam power) proton beam, in CERN’s North Area, fired at a stationary target made from pure wrought tungsten (W) [1]. The proton beam creates a local temperature range in the target core of 50 oC to 400 oC and local cyclic stresses between -100 MPa to +150 MPa. The target, which is currently being designed, is made from a series of W cylinders with diameter 250 mm and lengths ranging from 17 mm to 740 mm. As W is produced primarily from a powder metallurgy process, despite the further compaction through thermomechanical process such as hot rolling, the final product may still contain cavities. As such the maximum allowable defect size must be defined.

Abstract
Knowledge of the melt pool geometry of a Laser Powder Beam Fusion (PBF-LB) process is essential for
producing parts of the highest quality. A variety of numerical simulation tools and analytical
calculations can be used to predict a stable process window, significantly reducing the number of
experiments required. Various parameters (e.g. scan speed, laser power, beam size) are considered as
their interaction influences the melt pool dynamics, dimensions and any potentially resulting
microstructures.
There is a considerable diversity in approach and a lack of consensus on required accuracies. Fluid
dynamics simulations can require a considerable amount of expertise and become computationally
intensive, whereas more easy to use simulation tools such as the Thermo-Calc AM module are more
accessible and provide faster results and may be sufficient for most purposes.
This study compares different numerical and analytical methods for predicting the melt pool
geometries of LPBF-produced molybdenum and tungsten, which are then compared with experimental
results.

Abstract
The microstructure of K-doped tungsten sheets is critical for high-temperature applications. In this study the effects of various factors on the recrystallization behavior and resulting microstructure of rolled K-doped tungsten sheets are investigated, using both in-situ (reflectivity) and ex-situ methods (EBSD, SEM, etc.). The analyzed influences include dopant variations (K, Al, Si), rolling process, annealing procedure, and K-distribution. The temperature treatment was performed in ultra-high vacuum with direct resistive heating.

The recrystallization behavior of K-doped tungsten sheets is closely connected to the K-doping and the respective bubble formation. The K-bubble distribution, and thus the resulting microstructure and recrystallization behavior, is correlated to the dopant concentrations (K, Al, Si) in the sinter ingot and the degree of rolling. The annealing process itself has only limited impact on the K-bubble distribution. However, the recrystallization temperature and the resulting microstructure can be influenced by the annealing procedure, especially by the heating rate, and are found to be closely connected. Based on these insights, strategies for optimizing the microstructure of K-doped tungsten sheets are discussed.

Abstract
The aim of this paper is to research the influence of mechanical properties and microstructure of potassium-doped tungsten alloy plates at different rolling fires. Potassium-doped tungsten plates of two compositions were rolled in three and four firings, respectively, followed by microhardness and SEM characterisation. The results show that after annealing at 1350 ℃, the microstructure of the two potassium-doped tungsten alloy plates are still dominated by fibrous, part of the microstructure occurs response, and equiaxial grains are produced at the grain boundaries; when the temperature is increased to 1500 ℃, the percentage of equiaxial crystal grains reaches 95%, the two potassium-doped tungsten alloy plates reach the recrystallization temperature, and the hardness is reduced drastically. it's worth mentioning that for high potassium-doped tungsten alloy plate, the number of rolling fires has little effect on their hardness. However, for low potassium-doped tungsten alloy plate, the microhardness of three-fire rolling is much higher than that of four-fire rolling.

Abstract
Tungsten holds a high melting temperature of 34200C and is considered "difficult-to-fabricate". The main useful properties are: radiation shielding, heat resistance, high strength at high temperatures and high density. The classical method for tungsten solidification and forming is through sintering of pressed tungsten powder or tungsten heavy metal alloys (WHA) to either net shape or plastic deformation or machining.
Additive Manufacturing (AM) or 3D printing provides numerous shaping options and versatilities for fabrication processes. Thus, AM take a place when the traditional methods will not meet the geometrical, economic or quick prototyping designs.
Most of the metallic additive manufacturing (AM) techniques are based on powder particles. BEAM (SLM, EBM) and Direct Energy Deposition (DED) (Powder or wire) are mainly directed for pure tungsten.  Pellets Fused Deposition Modeling (PFDM) and Binder Jetting (BJ) are adapted for WHA and Poly-Tungsten. Photo polymerization (SL, DLP) and Laminated Engineering (LOM) are selected for WHA powders.
This survey will present the specific selection for application need by processing pure tungsten, WHA and Tungsten-Polymer.

Abstract
The most common Mo based alloy TZM contains carbon among other additions and shows enhanced strength and creep resistance as well as a higher recrystallization temperature compared to pure Mo. In general, alloying increases the complexity of the sintering process. For building up a comprehensive sintering model for TZM a stepwise procedure was started by sintering Mo with carbon addition only. Lab furnace experiments with gas monitoring and chemical analyses of the sintered samples were performed. Based on the experimental data a thermo-chemical-fluid dynamic finite element model was developed. The results give insight to the interaction of carbon and the residual oxygen in the powder blend and the sintering atmosphere. The kinetics of the relevant chemical reactions drive the decrease of these elements during sintering. The model displays the inhomogeneous distribution of carbon in the sintered body.

Abstract
Additive Manufacturing (AM) using Powder Bed Fusion (PBF) has facilitated the manufacturing of tungsten parts with complex geometries, and substantial research has been conducted in this field over recent years. However, bulk tungsten parts built with laser beam PBF (PBF-LB) is prone to cracking due to high residual stresses induced by the process.
The deflection speed of the beam in electron beam powder PBF (PBF-EB) is orders of magnitude higher than PBF-LB. Inertia-free high deflection speed of the electron beam facilitates unique scanning strategies enabling capabilities such as thermal management, microstructure tailoring, etc. In this study, we demonstrate manufacturing of fully dense and crack-free pure tungsten and explore innovative spot melting strategies. Process-microstructure-properties relationships for different e-beam scanning patterns with different powder forms are investigated. Video material will be used for illustration.
We will present parts with geometries suitable for plasma facing walls in fusion reactors showing the capability of printing defect free, low oxygen, bulk parts of considerable size made at high production rate enabled by high beam power processing.

Abstract
The increasing demands for high-performance refractory alloys in aerospace manufacturing call for optimized solutions that reduce costs, enhance sustainability, and meet performance challenges. Using the Materials by Design™ approach and ICME tools, alloy development is streamlined, minimizing experimental trials and accelerating production. Tanbium —a niobium (Nb), tantalum (Ta), titanium (Ti), and tungsten (W) alloy—, engineered for high-temperature space propulsion, exemplifies this process—delivering superior oxidation resistance, and strength retention compared to conventional alloys like C103. Initial thruster tests show promising results for next-generation aerospace applications, highlighting the effectiveness of tailored alloy design for future production needs.

Abstract
Mo-based alloys are particularly promising as they exhibit superior strength and creep resistance compared to Ni-based superalloys. However, oxidation/corrosion resistance, required to withstand aggressive atmospheres, and ductility/toughness, needed for failure tolerance, still display substantial barriers for these materials. Mo and most of its alloys suffer from catastrophic oxidation (“pesting”) above 500°C by the oxidation to MoO3, which evaporates due to its high vapor pressure. In contrast, Cr is usually considered as passivating element that forms dense Cr2O3 scales. However, Cr-based alloys suffer from scale spallation and nitridation when being exposed to air at high temperatures. Recently, an outstanding combination of resistance against oxidation in air in the critical temperature range and ductility even at room temperature was identified for a Cr-Mo-Si solid solution. In the present contribution, we report on our recent achievements regarding the dependence of critical properties on chemical constitution and microstructural condition, most notably (i) pesting resistance, nitridation and scale spallation at relevant temperatures as well as (ii) ductility at low temperatures.

Abstract
New applications in various industries require advanced joining techniques for refractory metals. Solid-state welding methods, such as diffusion bonding, are preferred as they do not require filler material. However, diffusion bonding for refractory metals is challenging due to their high melting points and stiffness. Additionally, joining ceramics to refractory metals poses difficulties, as cracks often form during the process.
This study focuses on joining similar refractory metals using diffusion bonding and on joining refractory metals to ceramics through brazing. Small-scale tests were conducted to understand key process parameters and improve design. Bonding areas were analyzed using non-destructive and destructive testing, and results were scaled to industrial-sized samples. For similar refractory metals, a homogeneous bond quality was achieved with no visible distinction between the bonding interface and the bulk material. In joining ceramics to refractory metals, a crack-free sample with uniform bond

Abstract
In this paper, W-4Re-0.27HfC alloy was synthesized using powder metallurgy and subsequently annealed at 1750 °C, 2000 °C and 2100 °C for 2 h to obtain varying microstructures. Creep tests were conducted under vacuum conditions at 2000 °C and 40 MPa. The microstructure morphology and composition of the microstructure were analyzed by SEM and EPMA. The effects of grain size, texture and dislocation density on the creep properties were examined through EBSD. Additionally, the interaction mechanism between the second phase and dislocations was investigated via TEM. The results indicate that with increasing annealing temperature, the grain size increases to 17.8 μm, 20.4 μm and 21.3 μm, respectively. However, the sample annealed at 2000 °C exhibits superior creep properties with a creep life of 5.4 h and a steady-state creep rate of 3.28×10-6. The creep performance is comprehensively affected by multi-scale factors such as grain size, impurity segregation, grain orientation and second phase.

Abstract
Nb-Al2O3 refractory metal matrix composites are promising materials for next-generation production technologies due to their ability to withstand high temperatures, mechanical stresses in harsh environments. The manufacturing method plays a critical role in achieving these properties. Factors such as porosity, density, and particle size are essential to obtain the desired thermal and mechanical properties, while applied pressure and the sintering regime significantly influence the composites' mechanical performance. In this study, Nb-Al2O3 composites with different alumina particle sizes were produced using casting, field-assisted sintering, and cold-isostatic pressing techniques. The mechanical properties at 1300 °C were evaluated by compression, stress relaxation, and creep tests. The results were analysed by comparing the initial porosity values, alumina particle sizes, and metal-to-ceramic ratio of the composites. Microstructural analysis before and after the mechanical tests revealed the deformation mechanisms. The findings indicate that higher initial porosity and larger alumina particle sizes adversely affect mechanical properties. Moreover, increasing the Nb-content led to more plastic behaviour under compressive stresses and reduced creep resistance.

Abstract
In this study, the effect of tungsten content and thermo-mechanical treatment on the microstructure and crystallographic texture of W-Ni-Fe alloys have been investigated. Tungsten content was varied between 90-98% and the Ni:Fe ratio 7:3 and the alloys were liquid phase sintered at 1500°C. The as-sintered alloys were subjected to swaging to upto 90% reduction in area and annealed at temperatures ranging from 1000°C to 1500°C. The resulting mechanical properties were correlated to the bulk and micro-texture and resulting dislocation alignment as observed though TEM studies.  EBSD studies indicate that matrix phase accommodates more strain in the early stages of deformation and eventually results in the onset of micro-shear band formation. The tungsten phase on the other hand showed the presence of large orientation gradients accompanied with significant flattening and elongation of grains. At higher rolling reductions (effective true strain of −2.66), extensive shear bands spanning across several tungsten particles and the matrix were observed in the microstructure, which in turn had implications on the evolution of the crystallographic texture.

Abstract
In this study, 93W-Ni-Fe alloy with excellent properties were synthesized using an in-situ synthesis method consisting of deep deoxidization, sintering and deformation processing. The mixture of tungsten oxide (WO3), nickel oxide (NiO) and iron oxide (Fe2O3) were reduced by H2-Ar mixed gases. The effect of reduction temperature, Ar percentage in the H2-Ar mixed gases, sintering temperature on the phase composition, morphology, particle size and properties were discussed. The experimental results showed when the Ar percentage in the H2-Ar mixed gases were 20-40%, and reaction temperature in deep deoxidization stage was in the range of 750-900 ℃, the W-Ni-Fe composite powder with the average particles size of 0.19-0.36 μm could be prepared. After the low-temperature sintering and deformation processing, the tensile strength and percentage elongation of prepared W-Ni-Fe alloy specimen reached the maximum value of 1573 MPa and 10.7 %, respectively.

Abstract
Mo-Ti-Al-based alloys are promising candidates for high-temperature applications due to their low density, excellent high-temperature mechanical properties, and deformability at room temperature. In this study, the structural stability and ductility of Mo-Ti-Al ternary BCC structures over a broad range of compositions were systematically investigated using DFT calculations to develop design guidelines for the Mo-Ti-Al alloys.
The formation enthalpy calculations indicates that each composition is intrinsically stable because of its negative values. However, some structures exhibit elastic instability as they do not satisfy Born’s criteria. The values of Pugh’s ratio evaluated from the elastic constants indicate that Mo-Ti-Al BCC structures calculated in the present study are intrinsically ductile. Additionally, both the formation enthalpy and Pugh’s ratio show characteristic, non-monotonic changes with variations in Mo-Ti-Al concentration. It provides useful ideas for the preliminary design of the Mo-Ti-Al-based alloys.

Abstract
Rotating anodes are components of X - Ray tubes, subjected to extreme thermal loads. Before the X - Ray tubes are used in the clinical field, the focal tracks of the rotating anodes are preconditioned, showing a surface crack network that provides relief from thermal stresses. As such, the necessity of fracture mechanical tools in their engineering is evident. Challenges are posed by the strong morphological dependence of fracture mechanical properties in typically used tungsten - rhenium alloys, as well as the limited thickness of focal tracks. In the experimental evaluation of toughness parameters samples must be taken directly from a routinely manufactured rotating anode, to ensure a comparable microstructure. This severely limits sample size and raises the question of the validity of common fracture mechanics concepts. In the following such small - scale samples for focal track material were designed and employed to measure physically meaningful toughness values. Furthermore, the brittle to ductile transition was investigated, complimented with a fractographic study. Additionally, composite beam samples were designed to study the crack tip - interface interaction and stress intensity factors for the composite beam case were applied using a Green's functions approach.

Abstract
This study investigates the heat resistance, insulation performance, and damage behavior of full-tungsten Langmuir probes used in ITER under high heat loading conditions. Utilizing the 60kW electron beam testing platform at the Southwest Institute of Physics, the probes were subjected to high heat flux tests under 10MW/m² steady-state heat load, 20MW/m² transient heat load, and 15MW/m² high-parameter steady-state heat load. The experimental results showed that the full-tungsten Langmuir probe could withstand 10MW/m² heat load for 100 minutes, 10MW/m2 for 5000 cycles and 20MW/m² heat load for 300 cycles. Under the 15MW/m² condition, the probe surface showed no significant damage within the first 1000 cycles, but cracks appeared after 3000 cycles, with recrystallization behavior observed on the surface of one Langmuir probe. Further non-destructive examination using the Energy-Resolved Neutron Imaging (ERNI) instrument at the China Spallation Neutron Source (CSNS) showed that failures of Langmuir probe may be resulted from cracking and fragmentation of the insulation layers of probes.

Abstract
State of the art high-pressure lines and connections are made from steel. Therefore, applications are limited by the temperature or the corrosive attack of the media to be transferred. Refractory metals show excellent high temperature performance and corrosive resistance, especially against oxidic melts or molten metals. The development of a connection out of refractory metal enables new applications.
The direct copy of a steel design fails, for instance because of galling preventing multiple opening and closing of the connection. To reduce the number of experimental trials a design study by means of numerical simulation was performed including different combinations of refractory based materials. The design features to be optimized were rated by their effect on a comprehensive set of targets, e.g. the contact pressure at the interfaces or the level of plastic deformation.
Finally, real components were built and exposed to hydraulic pressure drop measurements which confirmed pressure tightness to more than 2000 bar.

Abstract
Lithography-based Metal Manufacturing (LMM) is an additive manufacturing technology that creates metal components through the process of photo-polymerization with subsequent debinding and sintering. One challenge with this method is the ability of light to penetrate material layers, which can be limiting especially for darker materials and fine powders, such as tungsten heavy alloys. By carefully selecting appropriate polymeric binder compositions and testing both a laser-based (SLA) and a projector-based (DLP) approach, a stable solution that enables the production of functional parts with intricate designs and high feature resolution was developed. After sintering, the parts reached full density, and a thorough analysis was performed to evaluate the impact of this binder-based process on microstructure formation, impurities and mechanical properties.

Abstract
As a structural-functional integrated material, the improvement of service performance in tungsten-copper (W-Cu) composites strongly depends on their exceptional comprehensive properties. It was found that the configuration plays a significant role in their comprehensive properties. In our work, W-Cu composites with different types of configurations were designed and prepared by newly developed techniques. Ultra-high compressive strength (1900 MPa) and high conductivity (32.8%IACS) were achieved in W-25Cu composite by nanostructuring the tungsten phase rather than reducing the grain size. Synergistic increase in hardness and conductivity was realized through dispersion of ultrafine tungsten particles within copper matrix. The compressive strength, wear resistance, and electrical conductivity were concurrently enhanced by constructing a layered hierarchical structure consisting of alternating copper layers and nano W-Cu layers. Additionally, a self-assembled lamellar architecture was successfully engineered in the W-Cu system, resulting in simultaneous enhancement of strength and conductivity while maintaining high plasticity. Our studies highlighted the profound influence of tungsten phase's size, shape and distribution, as well as configuration between tungsten and copper phases on the comprehensive properties of W-Cu composites.

Abstract
The defocusing of Gaussian laser spots is an established method in Powder Bed Fusion - Laser Beam (PBF-LB) of metals to increase spot sizes and thereby associated manufacturing rates. However, the resulting effects of this beam widening technique on the melt pool characteristics in the Additive Manufacturing (AM) of molybdenum have not yet been described with Computational Fluid Simulation (CFD) backed data. Due to their extraordinary material properties, such as their extremely high melting points and thermal conductivities, e.g. 2620 °C and 142 W/m K (at 20 °C), respectively for molybdenum, refractory metals and alloys demonstrate specific melt pool characteristics compared to non-refractory ones. Therefore, CFD simulations were performed using FLOW-3D and subsequently validated by experiments on commercially pure molybdenum. Thus, this work offers a valuable insight into the temporally limited fluid dynamical processes of a melt pool during the AM of molybdenum with various defocused Gaussian laser beams to describe the potential formation of keyhole pores and Kelvin-Helmholtz instability induced surface roughness in the solidified melt track.

Abstract
Tungsten heavy alloys (WHA) are commonly praised for their high density and mechanical performance, in various fields. This is particularly true for aeronautics and Defense applications (such as kinetic energy penetrators), requiring a compromise between strength and ductility, along with high impact toughness.

These characteristics are achieved, in a solid-liquid sintering routine under hydrogen, by thermo-mechanical process proficiency associated with fine microstructure understandings.

Multi-scale characterization of the microstructure of a sintered W-Ni-X WHA was performed after specific processing steps, involving heat treatment and swaging operation (with X being an alloying metallic element such as Fe, Co, Al, Mn…). The results outlined the various impacts of heat treatment and anisotropic deformation in the matter of phase nature, size and morphology, interfaces characteristics and local strain variation.
In addition, a thermodynamical study of the system was carried out to better understand the nature of the phase transformations involved.

Whenever correlated with the mechanical properties of the material, the results are keys on improving future designed WHA through an optimized process.

Abstract
Mo and its alloys, due to their high chemical stability and excellent resistance to neutron radiation, possess extensive application potential in the nuclear industry. Notably, MoRe alloys incorporating Re demonstrate superior performance attributed to the Re effect. However, the embrittlement issue associated with welded MoRe joints has restricted their widespread adoption. This research centers on Moe14Re alloy sheets, adopting an innovative approach: initially depositing a thin C film onto the welding interface of Mo14Re sheets via magnetron sputtering, succeeded by electron beam welding. This technique facilitates in-situ synchronous carburizing during the welding operation. The outcomes reveal heightened hardness and tensile strength in the welded joints.The fracture mode changes from inter granular fracture to trans granular cleavage-like fracture. The research results can promote the development of technologies for manufacturing welding MoRe alloys.

Abstract
MoSiBTiC alloys are a type of Mo-based metal-matrix in-situ composites attracting much attention as the next generation of super heat-resistant metallic materials. MoSiBTiC alloys inherit the excellent high-temperature strength of conventional Mo-Si-B alloys, and in addition, their room-temperature fracture toughness has been improved to a level exceeding 15 MPa·m1/2 by the addition of TiC. Therefore, the purpose of this study is to clarify the toughening effect of TiC on Mo-Si-B alloys by investigating a wide range of TiC compositions. In this study, MoSiBTiC alloys were prepared by varying the TiC composition from approximately 5 mol% to 17.5 mol%. The results were then compared with those of the MoSiBTiC alloys reported previously by Moriyama, with the TiC compositions at 7.5 mol% and 10 mol%. The highest fracture toughness value of 15.8 MPa·m1/2 was obtained at the highest TiC composition of approximately 17.5 mol%. From the results obtained, it is considered that the three-dimensional network microstructure of primary TiC may contribute to the high fracture toughness.

Abstract
W-based materials are promising candidates for plasma-facing applications since they have
high melting temperatures, high thermal conductivity, low activation levels, high sputtering threshold
energy, and low tritium retention. However, workability could be problematic because of these
materials’ thermo-mechanical characteristics. Indeed, tungsten is hard and brittle, and the use of
mechanical tooling systems should be avoided, therefore there are strong design limitations. Laser-
Based Powder Bed Fusion (PBF-LB/M) is an additive manufacturing technique specially developed
for metals. One interesting perspective in the nuclear fusion research field is the possibility of using
additive manufacturing for developing and realizing components made of refractory metals. Some
issues still need to be fixed, for example, the fact that W undergoes cracking very easily. In this work,
the properties of pure W and in-situ W-based alloys processed via PBF-LB/M were examined.
Microstructural characterization and analysis of the cracking behavior followed a process parameters
optimization campaign to investigate the effects of the alloying elements introduced in the metal, and
performance evaluations like mechanical tests and post-process treatments have been carried out.

Abstract
Due to its high sputtering resistance, high melting point, low tritium retention and benign activity Tungsten is a promising plasma facing material (PFM) for fusion devices such as ITER and DEMO. However, plasma conditions can cause damage and erosion to tungsten plasma facing components (PFCs), leading to reduced lifetime of PFCs. Replacing PFCs is time-consuming and resource-intensive making efficient in-situ repair methods highly attractive. Low-pressure plasma spraying offers a fast, cost-effective way to repair damaged surfaces.
In this study, a design of experiments was used to reduce the number of trials and to identify factors that affect the coating quality on Eurofer steel, tungsten or even carbon fiber composite (CFC). Preheating of substrates reduced thermal shocks and residual stresses resulting from the thermal mismatch of coatings and substate materials. The coatings were evaluated for porosity, defects, surface roughness, thickness, and deposition efficiency. Fusion-relevant tests on 500 µm coatings with porosities below 1 % using the linear plasma device PSI-2 predicted sputter yield and deuterium retention. Future work will explore in-situ implementation and defect detection methods.

Abstract
The nucleation of various MoO2 starting materials was investigated on a laboratory scale during the second reduction step from MoO2 to Mo. It was found that a certain proportion of γ-Mo4O11 or a higher potassium content in the MoO2 samples as well as the addition of water to the hydrogen gas stream led to a shift towards the CVT process at a low reduction temperature of 900 °C. Not only spherical/polyhedral Mo nuclei but also intermediate, rod-shaped nuclei were detected using the γ-Mo4O11 containing MoO2 starting material at the beginning of the reduction. The influence of an increased potassium content in the γ-Mo4O11 containing MoO2 samples on the nucleation was also investigated. It was found that thicker and longer rods are formed, and the rod-shaped nuclei are present longer during the reduction process. Additionally, a mechanism for the formation of the rod-shaped nuclei is also proposed.

Abstract
In recent years, the demand for refractory metals in the space field has been increasing. Among them, Niobium (Nb) alloys are used as a material for satellite propulsion system thruster nozzles due to their specific strength, which is higher compared to other refractory metals in high-temperature operation environments. Additive Manufacturing (AM) methods using laser beam powder bed fusion (LB-PBF) have shown great potential in producing complex and optimized components like thruster nozzles in refractory metals like Nb, in Japan's space industry while also reducing cost and lead time. Niobium-based spherical C103 (Nb-10Hf-1Ti), FS85 (Nb-10W-28Ta-Zr), and FS85(-5W) (Nb-5W-28Ta-Zr) alloy powders were produced using the Electrode Induction-melting Gas Atomization (EIGA) at TANIOBIS GmbH. In this context, the AM processes for the aforementioned alloys were developed using both the M100 and M290 machines developed by EOS Gmbh. The microstructures of the AM parts were investigated using XRD, SEM, and EBSD. Finally, the mechanical properties of each AM alloy were compared in the as-built, stress-relieved (SR), and solution-treated (ST) conditions at room temperature and in a vacuum at temperatures ranging from 1200℃ to 1400℃.

Abstract
Refractory metals and alloys are used in several advanced manufacturing industries due to their unique high temperature properties. The breadth of their commercial adoption is dependent upon factors such as unit costs, throughput, tool-wear, and defect rates.  Traditional subtractive machining of refractory metals and alloys has proven costly and difficult.  Likewise, additively produced parts often require secondary subtractive machining to achieve required surface finishes.

Halocarbon Metalworking Fluids provide superior performance in the machining of refractory metals and alloys. Several U.S. National Labs and commercial customers have realized over 20X+ throughput, 5X+ tool life and 200-500% better surface finish using Halocarbon Metalworking Fluids vs. incumbent fluids to machine these metals/alloys (W, Ta, Mo, Nb, Ti, Inconel, etc.).  

Halocarbon Metalworking Fluids are safe, non-hazardous and extremely easy to clean. They are chemically inert, nonflammable and have no flashpoint further enhancing their safety in use and eliminating the requirement for biocides to extend the life of the fluids.  

Halocarbon will present currently available data demonstrating the value proposition of their synthetic fluorinated metal working fluids to customers.

Abstract
Additive manufacturing (AM) has transformed the production of tungsten alloys, valued for their density, strength, and ductility. This study investigates material extrusion (MEX) techniques, focusing on optimizing sintering post-treatments to improve mechanical properties. The results show that a 96W-2.7Ni-1.3Fe alloy achieved a high density of 99.1%, contiguity of 0.63, tensile strength of 801 MPa, and elongation of 22.1%. MEX has effectively addressed challenges like pore elimination, crack reduction, and phase mitigation, which have historically hindered tungsten alloy production. Through precise control over green body printing and solvent debinding, nearly full-density structures with exceptional hardness, transverse rupture strength, and fracture toughness were obtained. These advancements position tungsten alloys for applications in aerospace, resource extraction, manufacturing, and electronics, where high wear resistance, thermal stability, and dimensional precision are essential. Moreover, MEX enables the efficient fabrication of ultrafine grain tungsten alloy complex structures with minimal material waste.

Abstract
Tungsten is the primary candidate material for the plasma facing components of future fusion reactors but suffers from poor mechanical properties. Rhenium is an established alloying addition that is used to increase its ductility but there is a lack of available mechanical testing data. This study therefore aims to investigate the mechanical properties of rolled W and WRe plate using sub-scale mechanical testing methods including 3-point bending and nanoindentation. As-rolled and recrystallised plates are investigated to provide insight into the impact of prior deformation on the mechanical response. Microstructural characterisation is performed using Electron Backscatter Diffraction (EBSD) and X-Ray Diffraction (XRD). These results confirm that the addition of Re increases plastic deformation at room temperature and decreases the yield strength. Despite this the formation of Re during neutron irradiation is associated with a decrease in mechanical performance, which is attributed to the formation of nanoscale precipitates and voids.

Abstract
MoSiBTiC alloys exhibit a wide range of excellent properties, such as high-temperature creep strength and good room temperature fracture toughness. Since the material properties are highly dependent on their complex microstructure, it is important to understand the relationship between the material properties and the microstructure. The microstructure is composed of Mo solid solution, Mo5SiB2, TiC, and Mo2C phases, with a lamellar structure of Moss and TiC and fine precipitates. Two key steps are essential to analyze the relationship between the properties and microstructure: image segmentation of the constituent phases and quantification of the microstructure. In this study, many scanning electron microscopy images of MoSiBTiC alloys were prepared to investigate how effectively machine learning techniques could reduce the time required for the image segmentation of complex microstructures. Machine learning methods reduced segmentation time for a single image from approximately three days to 20 minutes. Additionally, the segmented images were used to quantify the microstructural features of MoSiBTiC alloy using various parameters. As a result, the microstructures were well characterized geometrically and topologically.

Abstract
MHC 合金（含有 0.8-1.2 wt% 铪和 0.05-0.12 wt% 碳的钼合金）与纯钼相比，由于在钼基体中形成 HfC 而具有优越的再结晶温度，因此在高温下具有优势。在本研究中，通过放电等离子烧结制备了 TiC （3 wt%， 6wt%，9wt%） 增强的 MHC 复合材料。根据其密度、微观结构和机械性能（如显微硬度和高温强度）对制备的复合材料进行了表征。结果表明，随着TiC含量的增加，MHC-TiC复合材料中Mo晶粒的尺寸受到显著抑制，材料的高温力学性能得到改善。在 MHC-TiC 复合材料中发现了各种第二相。TiC 的添加同时降低了 MHC 的密度。MHC-TiC 合金是航空航天和能源行业广泛应用的有前途的候选者。

Abstract
Development of a Monte-Carlo model for radiation transport in solid X-ray targets and its implementation within COMSOL Multiphysics are presented. The fully quantitative and energy-conserving model describes electron and photon shower evolution from an electron beam incident on a solid target as typically found in stationary or rotating X-ray anodes. All relevant particle interactions with target atoms as well as the production of X-ray photons by bremsstrahlung emission, secondary electrons, and electronically excited target atoms are considered. Fundamental dosimetry quantities such as photon fluence, photon energy fluence, and absorbed dose are computed. For an isotropic medium, results obtained for an ideal monoenergetic electron pencil beam can be transformed to realistic e-beam shapes using the convolution theorem. Exemplary application of the model is demonstrated for a tungsten target exposed to a 50 keV e-beam. The model will provide detailed heat source distributions for subsequent nonlinear cyclic thermo-mechanical finite element analyses for strength assessments of X-ray anodes potentially also accounting for effects related to focal track wear.

Abstract
Conventional mechanical alloying processes for oxide dispersion strengthened (ODS) refractory alloys have reached certain limits in further improving their properties. In this study, we successfully demonstrated the ultrasonic spray pyrolysis (USP) technique combined with hydrogen reduction to synthesize ODS W alloy powders with uniformly dispersed Y2O3 nanoparticles. The synthesized powders exhibited micro-sized secondary particles composed of primary particles with a size of about 30 nm. Thus, they secured both formability and sinterability, essential for producing high-quality sintered bodies. Sintered specimens were fabricated using conventional uniaxial compression and pressureless sintering to confirm the size and distribution of Y2O3 nanoparticles. After sintering, they exhibited a grain size of approximately 3 μm and a relative density of more than 96%, and Y2O3 nanoparticles with a size of approximately 50 nm were uniformly dispersed. In addition, they show an excellent hardness of approximately 7.2 GPa. These results indicate the successful synthesis of ODS W powder with desirable structure and highlight its potential in various applications, particularly those requiring high-quality sintered bodies with enhanced mechanical properties.

Abstract
Kratos SRE (KSRE), formerly Southern Research, in Birmingham, AL, USA, is known worldwide for their expertise in high temperature testing of materials.  With capabilities in a variety of mechanical, thermal, and non-destructive property evaluation, KSRE can provide a full suite of property measurements over a wide range of temperatures.  Test temperatures range from -269C to 2760C to meet a wide variety of applications.

Key mechanical test capabilities include tension, compression, torsion, flexure, fatigue, and creep.  Thermal test capabilities include thermal expansion, thermal conductivity, specific heat capacity, and thermal diffusivity. Specialized testing capabilities include emissivity, permeability, and dielectric properties over various temperature ranges.  Custom test development and techniques are also available.

KSRE has developed specific testing expertise and processes for testing refractory metals at elevated temperatures in air, inert, vacuum, and partial pressures.  An overview of KSRE’s testing capabilities specific to refractory metals will be presented.

Abstract
Advancing the application temperatures of various high-temperature applications, such as gas turbines or as metallic hot zones, pushes nickel-based superalloys to their limits. Meanwhile, innovative chromium-silicon-base (Cr-Si-) alloys demonstrate promising potential with their high melting temperatures and impressive corrosion resistance. The primary challenge with Cr-Si- alloys is the transition from ductile to brittle behavior due to its bcc structure below 640 °C. This transition temperature is significantly increased by impurities, whereas pure chromium experiences this transition between -25 °C and 50 °C depending on pretreatment. However, by adding molybdenum to the Cr-Si-alloy, the transition temperature can be reduced to about 400 °C. Furthermore, additional reduction is achievable through appropriate microstructure modification. Thus, in the presented study a manufacturing procedure was elaborated to prevent A15 nucleation at the grain boundaries. Avoiding the nucleation of the A15 phase decreased the ductile-brittle transition temperature by approximately 40 %. The study demonstrates the potential of Cr-Si-Mo alloys for use in more efficient high-temperature applications.

Abstract
To study the recrystallisation behaviour and mechanical properties of different tungsten-based materials, different annealing processes were applied to pure tungsten, W-La2O3 , W-Re and W-Al-K alloy plates with a deformation of 97.5%. Followed by microhardness，EBSD and SEM characterisation. The results show that after annealing at 1250°C for 1h, the microstructure of pure tungsten plates transforms from fibrous to multi-jagged grains and reaches the recrystallisation temperature. Secondly, the starting recrystallisation temperature of W-La2O3 alloy is less than 1250 ℃, similar to that of W-Al-K alloy, but the complete recrystallisation temperature is more than 1550 ℃, which is much higher than that of W-Al-K and W-Re alloys. Therefore, W-La2O3 alloy plates has stronger recrystallisation inhibition ability and more excellent high temperature performance. Finally, although the W-Re alloy plate has a high initial recrystallisation temperature, but with the temperature increases, the microhardness decreases sharply or even falls below that of pure tungsten due to the softening effect of the Re.

Abstract
Tungsten heavy metal alloy (WHA) exhibits unique properties such as high density, excellent mechanical properties and high corrosion resistance due to the synergistic effect between the W matrix and binder phases. WHA powder is generally prepared by ball milling of metal element powders, but it is difficult to fabricate uniform and high-purity alloy powders due to agglomeration and contamination problems. Therefore, the powder synthesis process involving ball milling oxide powders and subsequent hydrogen reduction has been receiving much attention. However, there is a lack of systematic research on the effects of powder characteristics on the sinterability and microstructure of WHA. In this study, W-7 wt% Ni-3 wt% Cu alloy powder was prepared by ball milling and hydrogen reduction using WO3, NiO, CuO powders. The alloy powders are compacted and pressureless sintered in a hydrogen atmosphere. An optimum synthesis condition is determined based on the observed microstructural characteristics of prepared powders. In addition, the dependence of the properties on the fabrication process was discussed.

Abstract
Due to the thermal limitations of Ni-based superalloys, there have been continuous attempts to develop next-generation superalloys to replace them. In particular, refractory metal-based superalloys that can withstand extreme heat and pressure environments are being developed to improve the efficiency and fuel economy of gas turbines. Mo-Si-B alloys have excellent high-temperature mechanical properties and oxidation resistance. Recent research has focused on significantly improving the mechanical properties of Mo-Si-B alloys at elevated temperatures using oxide dispersion strengthening. As a result, efforts have been made to achieve uniformly dispersed oxides, and ultrasonic spray pyrolysis (USP) is considered an effective approach to uniformly disperse oxide with various compositions. In addition, recent research has focused on spark plasma sintering (SPS) to address the challenge of reduced sinterability due to oxide addition. In this study, MoO3/La2O3 nanoparticles were prepared using USP and then reduced in hydrogen atmosphere. In addition, Mo-Si-B alloy was fabricated by complexing with Mo Silicide synthesized through mechnochemical process and sintering using SPS. The microstructure and mechanical properties of the La2O3 dispersed Mo-Si-B alloy were analyzed.

Abstract
The aim of this work was to weld graphite and TZM alloy by Ti foil in order to obtain stable structure applied to X-ray tube target. The microstructure and compositions on the interface were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. The tensile shear strength and hardness of the joints were studied. It is shown that the joint showed good  combination with no apparent defects under the optimal processing conditions. A transition layer with a thickness of approximately 433 um was formed, which is mainly composed of 76 um Ti2C0.06 and 100 um Mo9Ti4 and MoC. The hardness of the transition layer can reach 2000 HV, which is much higher than that of graphite and TZM alloy. The interfacial shear strength of the graphite and TZM joint is approximately 25MPa, which is close to the shear strength of graphite. Approximately 40% of shear fractures occured in graphite and 60% occured in the transition layer.

Abstract
Molybdenum rhenium material has better high temperature strength and room temperature plasticity than pure molybdenum metal, and has good chemical compatibility with alkali metal and nuclear fuel. It is a very potential candidate material in aerospace equipment energy system.Three kinds of molybdenum rhenium alloy bars were prepared by powder metallurgy. After forging deformation and stress relief annealing, the mechanical properties of molybdenum rhenium materials at room temperature and high temperature were tested and analyzed. It is found that with the increase of rhenium content, the tensile strength increases significantly, the elongation at room temperature decreases, and the elongation at 900 ℃ increases slightly. The microstructure and fracture morphology of the material were observed by means of metallography, SEM and EBSD. It was found that the microstructure of the material had different effects on the room temperature and high temperature properties of the material.

Abstract
In this study, alloys with nickel-tungsten ratios of 60:40, 50:50 and 40:60 were prepared by powder metallurgy and forged. The density and microstructure of alloys with different ratios of nickel to tungsten were investigated after sintering: the density increased, the tungsten phase size grew, and the grains were refined as the tungsten content increased. The effect of solid solution quenching treatment on the properties of the alloys was investigated: the results showed that solid solution quenching can improve the strength of the alloys, and the strength of the alloys with nickel-tungsten ratios of 60:40, 50:50, and 40:60 increased from 555 MPa, 595 MPa, 615 MPa to 880 MPa, 1025 MPa, 1025 MPa, respectively. The alloy with a nickel-tungsten ratio of 40:60 was forged with different deformation amounts: the tensile strength gradually increased with the increase of deformation magnitude, and the strength reached 1635 MPa when the deformation amount was 30%.

Abstract
The field of tribology, which focuses on friction and wear, is gaining increased attention due to the growing importance of the efficient and sustainable operation of machine elements. Nearly every industrial sector relies on machines and mechanical systems with moving parts in relative motion, making tribology crucial. In cases where liquid lubrication is not feasible, understanding the behavior of metallic surfaces in sliding contacts, including different oxides on the surfaces, becomes essential.
This research focuses on studying the friction and wear behavior of molybdenum and steel friction pairs in a ball-on-disk setup under ambient air and nitrogen atmosphere to analyze the role of oxidation and specific oxides. Experimental results will be presented at elevated temperatures and compared to measurements at room temperatures. The samples will be characterized using high-resolution techniques such as Raman spectroscopy, XPS, XRD, and TEM to provide insights into the mechanisms at play in the frictional contact between Mo and steel.

Abstract
The history of tantalum is fascinating, and I will explain why this remarkable element is widely used in electronics and the medical field, eventually leading to its application using additive manufacturing.

We will delve into the technical details of tantalum’s properties, exploring its significance in various industrial sectors. Additionally, we will investigate the advantages of working with this challenging material, particularly its need for controlled atmospheres during high-temperature production processes.

Abstract
In the future fusion reactors, plasma facing materials may subjected to an ultra-high thermal load of 20 MW/m2 during steady-state operation. To meet the material requirements under such harsh service environments, this study manufactured potassium-doped tungsten plates with thicknesses of 5 - 13 mm via a mass production route in the real industry. The effective content of the dopant is 80-100 ppm. The potassium evolution and its effects on the microstructure and thermal shock resistance were investigated. The results show that the room temperature conductivity of the material is 165.8 W/(m·K). The ductile-to-brittle transition temperature is below 200 ℃, and the recrystallization temperature is approximately 1775 ℃. After 1500 cycles of high heat flux (15 s on/15 s off, 20 MW/m2), the water-cooled mockup built by these plates presented no obvious plastic deformation and macro cracks on the surface of the material.

Abstract
Chromium is an attractive base element for the development of new high-temperature alloys due to its favorable properties, such as low density, high melting point and thermal conductivity, availability, as well as relatively low cost. However, there are challenges to overcome before chromium can be widely utilized, such as its inadequate corrosion resistance at elevated temperatures, particularly due to the formation of volatile species and nitridation. Alloying elements can successfully address these limitations. Silicon has been shown to be essential in reducing oxidation rates and promoting precipitation hardening by forming an intermetallic phase (A15). Additionally, molybdenum has been identified as another crucial alloying element, capable of improving both the high-temperature mechanical properties and limiting the nitridation of the chromium solid solution. The influence of Mo on the oxidation behavior of Cr-Mo-Si alloys in air at 1200 °C has been investigated. This study specifically focuses on the effects of molybdenum on the hot corrosion behavior of Cr-Mo-Si alloys, where Mo changes the attack mechanism by the highly acidic character of its oxide.

Abstract
Recently, due to its almost unlimited possibilities, there has been an increased interest in 3D printing techniques, also in areas related to the use of high-melting metals. These technologies bring a number of different positives, including a low waste amount, which is crucial when using critical materials, such as tungsten. Unfortunately, due to a number of specific properties, it is extremely difficult to produce good quality prints from metals like tungsten and molybdenum. To meet market expectations, we offer tungsten and molybdenum powders modified with rhenium, produced with the use of plasma spheroidization technology. Rhenium has been known for years for its special properties, including reduction of the ductile to brittle transition temperature (DBTT) in both tungsten and molybdenum (know as "rhenium effect"). As part of the work, spherical tungsten and molybdenum powders with various rhenium contents were produced, characterized by a good flowability, density and small specific surface area. Test samples were produced from these powders using the 3D printing method, which, compared to pure elements, were characterized by better density and lower porosity.

Abstract
Tungsten heavy alloy's remarkable properties, such as high density and strength, make it a material of choice for various industries, including defense, aerospace, and nuclear sectors. The ability to form parts like counterweights, shock absorbers, gears, and radiation shields underscores its versatility. The advent of 3D printing has revolutionized the manufacturing process, allowing for the creation of complex parts with reduced waste and fewer production steps. However, the development of suitable feedstock material is crucial for successful 3D printing. Metals typically require additives to achieve the necessary physical properties for printing. In the context of extrusion-based 3D printing, a blend of tungsten heavy alloy and organic binders has shown promise. Instruments like rheometers, SEM, and TGA are instrumental in characterizing these materials, ensuring they meet the stringent requirements for use in sophisticated printers like the Hydra model. This synergy of material science and advanced manufacturing techniques is paving the way for innovative applications and efficiencies in production.

Abstract
X-ray rotating anodes are used in medical imaging procedures such as computed tomography. Despite the outstanding thermophysical properties of refractory metal alloys, the high power introduced into the focal track leads to cyclic thermally induced stress in the material which can subsequently result in a crack network or local melting in the focal track.
In order to quantify the focal track damage after usage and calculate the resulting X-ray dose attenuation on a physical basis, high-resolution 3D data of the focal track surface is required, which is recorded using a computer vision system. Based on this data and a newly implemented GPU-accelerated evaluation method, the influence of geometric damage features has been calculated and validated using dose measurements. Hence, this method enables predicting the X-ray dose attenuation based on the surface morphology of the focal track. In addition, the correlation of characteristic features such as crack depths and surface roughness with the dose attenuation has been investigated.

Abstract
The Cantor alloy (FeCoCrMnNi) is a high-entropy alloy known for its excellent ductility, mechanical strength, and resistance to wear and corrosion. Fabrication methods include traditional powder metallurgy and spark plasma sintering (SPS). A common issue during sintering is carbon diffusion from the tool to the alloy's surface, often overlooked in literature. This study utilized the FAST/SPS method to synthesize a Cantor alloy with titanium added to the surface layer, as titanium has a higher affinity for carbon than chromium. The hypothesis was that Ti would bind the diffusing carbon, forming Ti carbide precipitates.
Compacts were prepared from the powder using cold pressing at 400 MPa. A mixture of 95 wt.% HEA and 5 wt.% Ti was prepared, surrounding the green compact in a 20 mm FAST/SPS die. Sintering occurred at 1050°C with a pressure of 50 N for times of 7.5÷60 minutes. Results indicated that adding titanium mitigated chromium depletion in the surface layer and enhanced hardness, achieving over 400 HV for longer sintering times compared to 150 HV for HEA alloy.

Abstract
Modern applications of fine wires demand ever increasing requirements in tensile strength, fatigue properties and defect levels. This study explores the development of high-strength tungsten (W) and tungsten-lanthanum (WL) fine wires with a focus on understanding the microstructure-property relationship. For the highest-strength wires it is crucial to fine-tune the chain of deformation and annealing steps to ensure drawability without compromising on tensile strength. Understanding this relationship is achieved by continuous mechanical testing and metallographic analyses throughout the process route to assess grain size distributions, the mechanical properties and defect occurrences from an initial diameter down to a final diameter of 25 µm. The investigations extend to the influence of the thermo-mechanical processing steps like sintering, forging, drawing and intermediary annealing treatments.
The resulting fine wires exhibit tensile strengths >5000 MPa, making them suitable for applications such as surgery robot actuator cables or nickel-diamond-coated cutting wires for silicon wafering. This comprehensive study provides insights into the microstructure-guided design of high-strength W-based fine wires, highlighting the importance in tailoring wire properties for different application fields.