Powder Metallurgy Processing of a WxTaTiVCr High-Entropy Alloy and Its Derivative Alloys for Fusion Material Applications

Abstract

The WxTaTiVCr high-entropy alloy with 32at.% of tungsten (W) and its derivative alloys with 42 to 90at.% of W with in-situ TiC were prepared via the mixing of elemental W, Ta, Ti, V and Cr powders followed by spark plasma sintering for the development of reduced-activation alloys for fusion plasma-facing materials. Characterization of the sintered samples revealed a BCC lattice and a multi-phase structure. The selected-area diffraction patterns confirmed the formation of TiC in the high-entropy alloy and its derivative alloys. It revealed the development of C15 (cubic) Laves phases as well in alloys with 71 to 90at.% W. A mechanical examination of the samples revealed a more than twofold improvement in the hardness and strength due to solid-solution strengthening and dispersion strengthening. This study explored the potential of powder metallurgy processing for the fabrication of a high-entropy alloy and other derived compositions with enhanced hardness and strength.

Science and technology in high-entropy alloys

“…High performance of HEA radiation-resistant materials provides a new idea for nuclear materials, and it has been used as the catalyst in the nuclear energy [97,[101][102][103]. Waseem et al [68] considered that the W x TaTiVCr as low/reduced-activation alloys have a promising future for fusion power plants.…”

“…Although there are more than four or five elements in HEAs [20], they tend to form a relatively-simple phase after solidification, such as FCC [21], BCC, or HCP [23,68] structures. However, with the extensive and deep research on HEAs, it is found that the alloys also contain ordered intermetallics, amorphous and nanocrystalline precipitates [19,47,69].…”

Thermodynamic Properties of Wx(TaTiVCr)1−x High‐Entropy(‐Like) Alloy and Influence of Tungsten Content

“…Specifically, refractory metal elements have relatively high melting points (Ti [1946 °C], Ta [3293 °C], V [2202 °C], Cr [2133 °C], Mo [2895 °C], Nb [2750 °C], Zr [2128 °C], Hf [2504 °C]), it is valuable to explore HEAs composed of these elements for high‐temperature applications in nuclear reactors as plasma facing materials (PFMs). Experimentally W x (TaTiVCr) 1− x ( x = 0.30–0.67) alloys have been fabricated and studied . For instance, using the vacuum arc melting technique, HEAs composed of refractory elements (Ti, V, Cr, Ta, or W) are studied .…”

“…As mentioned above, developing the tungsten alloys has always been a hot issue in optimizing the performance of nuclear fusion reactor, so exploring of new tungsten alloys with suitable properties has being done extensively . From viewpoint of improved properties of W‐based alloy with respect to the pure tungsten, multi‐component alloying is beneficial to further improve the properties of tungsten alloy.…”

“…From viewpoint of improved properties of W‐based alloy with respect to the pure tungsten, multi‐component alloying is beneficial to further improve the properties of tungsten alloy. For this reason, W‐rich high‐entropy alloys are inevitably promising materials in nuclear fusion reactor, hence have been studying in field of controlled nuclear fusion, and great progresses are made recently . Especially, the multi‐component random W x (TaTiVCr) 1− x alloys justly belong to the new family of high entropy alloys when x is in the range of 0.05–0.35 in terms of both composition‐based and entropy‐based definition.…”