Refractory metals
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Alloy design for intrinsically ductile refractory high-entropy alloys Open
Refractory high-entropy alloys (RHEAs), comprising group IV (Ti, Zr, Hf), V (V, Nb, Ta), and VI (Cr, Mo, W) refractory elements, can be potentially new generation high-temperature materials. However, most existing RHEAs lack room-temperatu…
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Development of a Refractory High Entropy Superalloy Open
Microstructure, phase composition and mechanical properties of a refractory high entropy superalloy, AlMo0.5NbTa0.5TiZr, are reported in this work. The alloy consists of a nano-scale mixture of two phases produced by the decomposition from…
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Lattice‐Distortion‐Enhanced Yield Strength in a Refractory High‐Entropy Alloy Open
Severe distortion is one of the four core effects in single‐phase high‐entropy alloys (HEAs) and contributes significantly to the yield strength. However, the connection between the atomic‐scale lattice distortion and macro‐scale mechanica…
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Unique Role of Refractory Ta Alloying in Enhancing the Figure of Merit of NbFeSb Thermoelectric Materials Open
NbFeSb‐based half‐Heusler alloys have been recently identified as promising high‐temperature thermoelectric materials with a figure of merit zT > 1, but their thermal conductivity is still relatively high. Alloying Ta at the Nb site would …
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Current Status of Research on the Oxidation Behavior of Refractory High Entropy Alloys Open
Refractory high entropy alloys (RHEA) are considered as novel promising high‐temperature materials for structural applications at ultrahigh temperatures primarily due to their attractive mechanical properties. By contrast, the oxidation be…
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Selective laser melting of high-performance pure tungsten: parameter design, densification behavior and mechanical properties Open
Selective laser melting (SLM) additive manufacturing of pure tungsten encounters nearly all intractable difficulties of SLM metals fields due to its intrinsic properties. The key factors, including powder characteristics, layer thickness, …
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Direct Metal Deposition of Refractory High Entropy Alloy MoNbTaW Open
Alloying of refractory high entropy alloys (HEAs) such as MoNbTaW is usually done by vacuum arc melting (VAM) or powder metallurgy (PM) due to the high melting points of the elements. Machining to produce the final shape of parts is often …
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Effects of Mo, Nb, Ta, Ti, and Zr on Mechanical Properties of Equiatomic Hf-Mo-Nb-Ta-Ti-Zr Alloys Open
Nowadays refractory high-entropy alloys (RHEAs) are regarded as great candidates for the replacement of superalloys at high temperature. To design a RHEA, one must understand the pros and cons of every refractory element. However, the elem…
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Alloys for application at ultra-high temperatures: Nb-silicide in situ composites Open
The paper reflects on the development of Nb-silicide based alloys vis-à-vis property goals and compares them with refractory-complex-concentrated-alloys (RCCAs) for their density, oxidation and mechanical properties. The Nb-silicide based …
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Manufacturing and Analysis of High-Performance Refractory High-Entropy Alloy via Selective Laser Melting (SLM) Open
Refractory high-entropy alloys (HEAs) have excellent mechanical properties, which could make them the substitutes of some superalloys. However, the high melting point of refractory HEAs leads to processing problems when using traditional p…
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Venting temperature determines surface chemistry of magnetron sputtered TiN films Open
Surface properties of refractory ceramic transition metal nitride thin films grown by magnetron sputtering are essential for resistance towards oxidation necessary in all modern applications. Here, typically neglected factors, including ex…
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WxNbMoTa Refractory High-Entropy Alloys Fabricated by Laser Cladding Deposition Open
WxNbMoTa refractory high-entropy alloys with four different tungsten concentrations (x = 0, 0.16, 0.33, 0.53) were fabricated by laser cladding deposition. The crystal structures of WxNbMoTa alloys are all a single-phase solid solution of …
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A Review of the Latest Developments in the Field of Refractory High-Entropy Alloys Open
This review paper provides insight into current developments in refractory high-entropy alloys (RHEAs) based on previous and currently available literature. High-temperature strength, high-temperature oxidation resistance, and corrosion re…
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A review of refractory high-entropy alloys Open
This work reviews recent progress in the alloy design, microstructure, and mechanical properties of refractory high-entropy alloys (RHEAs). What's more, the underlying strengthening mechanisms and deformation behavior are discussed. Compos…
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Effect of microalloying with silicon on high temperature oxidation resistance of novel refractory high-entropy alloy Ta-Mo-Cr-Ti-Al Open
The effect of 1 at.% Si addition to the refractory high-entropy alloy (HEA) Ta–Mo–Cr–Ti–Al on the high temperature oxidation resistance in air between 900 °C and 1100 °C was studied. Due to the formation of protective chromia-rich and alum…
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Surface oxidation mechanism of a refractory high-entropy alloy Open
High-entropy alloys (HEAs) synthesized using refractory elements are being strongly considered as candidates for high temperature structural applications. The role of compositional changes of HEA surfaces due to oxidation is crucial to sus…
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Predictive process parameter selection for Selective Laser Melting Manufacturing: Applications to high thermal conductivity alloys Open
There is growing interest in Laser Powder Bed Fusion (L-PBF) or Selective Laser Melting (SLM) manufacturing of high conductivity metals such as copper and refractory metals. SLM manufacturing of high thermal conductivity metals is particul…
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High-Temperature Oxidation of High-Entropic Alloys: A Review Open
Over the past few years, interest in high-entropic alloys (HEAs) has been growing. A large body of research has been undertaken to study aspects such as the microstructure features of HEAs of various compositions, the effect of the content…
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Functionally graded structures of refractory metals by wire arc additive manufacturing Open
Functionally graded components are usually preferred for severe and critical service conditions, thanks to the possibility of achieving different complementary material properties within the same structure. Wire + Arc Additive Manufacturin…
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Microstructure and Mechanical Properties of Nb–Ti–V–Zr Refractory Medium-Entropy Alloys Open
Low-density refractory medium entropy alloys (NbTiVZr, Nb0.5TiVZr, and NbTiV) were produced by vacuum arc melting, then heat-treated at 1,200°C for 1 h, water quenched, and finally annealed at 500°C for 0.5 h. Their respective microstructu…
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Temperature stability of thin film refractory plasmonic materials Open
Materials such as W, TiN, and SrRuO3 (SRO) have been suggested as promising alternatives to Au and Ag in plasmonic applications owing to their stability at high operational temperatures. However, investigation of the reproducibility of the…
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Nanocomposite Multilayer Binary Nitride Coatings Based on Transition and Refractory Metals: Structure and Properties Open
One area of constant interest in many fields of industry is development of functional multilayer coatings that possess excellent performance characteristics. That is why in our brief review the results of studies of structure and propertie…
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Review on Preparation Technology and Properties of Refractory High Entropy Alloys Open
Refractory high entropy alloys have broad application prospects due to their excellent comprehensive properties in high temperature environments, and they have been widely implemented in many complex working conditions. According to the la…
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Development of ultrahigh-entropy ceramics with tailored oxidation behavior Open
In the last decade, single-phase high-entropy materials have attracted considerable research interest owing to their unexpected existence and unique combinations of properties. Recent development of 5-cation high-entropy carbides (HECs) ha…
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Design of BCC refractory multi-principal element alloys with superior mechanical properties Open
The correlations between tensile properties and some common parameters in BCC refractory multi-principal element alloys (RMPEAs) have been systematically investigated. The findings can be used as guidelines for the alloy design. We found t…
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Synergetic strengthening in HfMoNbTaTi refractory high-entropy alloy via disordered nanoscale phase and semicoherent refractory particle Open
We propose a novel strengthening strategy that involves the introduction of a high-entropy nanoscale phase (HENP) and semicoherent refractory nanoparticle into the A2 matrix of an as-cast equimolar HfMoNbTaTi refractory high-entropy alloy …
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Effect of Rare Earth Metals (Y, La) and Refractory Metals (Mo, Ta, Re) to Improve the Mechanical Properties of W–Ni–Fe Alloy—A Review Open
Tungsten heavy alloys are two-phase metal matrix composites that include W–Ni–Fe and W–Ni–Cu. The significant feature of these alloys is their ability to acquire both strength and ductility. In order to improve the mechanical properties of…
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A Nitride-Reinforced NbMoTaWHfN Refractory High-Entropy Alloy with Potential Ultra-High-Temperature Engineering Applications Open
Refractory high-entropy alloys (RHEAs) have promising applications as the new generation of high-temperature alloys in hypersonic vehicles, aero-engines, gas turbines, and nuclear power plants. This study focuses on the microstructures and…
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Microstructural Degradation of the AlMo0.5NbTa0.5TiZr Refractory Metal High-Entropy Superalloy at Elevated Temperatures Open
Refractory metal high-entropy superalloys (RSA), which possess a nanoscale microstructure of B2 and bcc phases, have been developed to offer high temperature capabilities beyond conventional Ni-based alloys. Despite showing a number of exc…
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Microstructure and properties of Al0.5NbTi3VxZr2 refractory high entropy alloys combined with high strength and ductility Open
Novel lightweight Al0.5NbTi3VxZr2 (x = 0.5, 1.0, 1.5) refractory high entropy alloys were synthesized by vacuum arc melting. The microstructure evolution and mechanical properties of Al0.5NbTi3VxZr2 alloys were analyzed. All Al0.5NbTi3VxZr…