Spark plasma sintering of tungsten-based WTaVCr refractory high entropy alloys for nuclear fusion applications

• Published in: International journal of minerals, metallurgy and materials Vol. 31; no. 1; pp. 146 - 154
• Main Authors: Yoo, Yongchul, Zhang, Xiang, Wang, Fei, Chen, Xin, Li, Xing-Zhong, Nastasi, Michael, Cui, Bai
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.01.2024; Springer Nature B.V; Department of Mechanical & Materials Engineering,University of Nebraska-Lincoln,Lincoln,NE 68588,USA%Nebraska Center for Materials and Nanoscience,University of Nebraska-Lincoln,Lincoln,NE 68588,USA%Department of Nuclear Engineering,Texas A & M University,College Station,TX 77843,USA%Department of Mechanical & Materials Engineering,University of Nebraska-Lincoln,Lincoln,NE 68588,USA; Nebraska Center for Materials and Nanoscience,University of Nebraska-Lincoln,Lincoln,NE 68588,USA; Springer Verlag
• Subjects: Alloys; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Compressive strength; Corrosion and Coatings; Electron backscatter diffraction; Electron diffraction; Fusion reactors; Glass; Grain size; Hardness; High entropy alloys; Materials Science; Materials selection; Mechanical alloying; Metallic Materials; Metallurgy; Metallurgy & Metallurgical Engineering; Mining & Mineral Processing; Nanohardness; Natural Materials; Nuclear fusion; Plasma sintering; Powder metallurgy; Refractory alloys; Research Article; Rockwell hardness; Room temperature; Sintering (powder metallurgy); Spark plasma sintering; Surfaces and Interfaces; Thin Films; Tribology; Tungsten; X-ray diffraction; refractory high entropy alloy; fusion reactor; spark plasma sintering; plasma-facing material
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-023-2711-9

W-based WTaVCr refractory high entropy alloys (RHEA) may be novel and promising candidate materials for plasma facing components in the first wall and diverter in fusion reactors. This alloy has been developed by a powder metallurgy process combining mechanical alloying and spark plasma sintering (SPS). The SPSed samples contained two phases, in which the matrix is RHEA with a body-centered cubic structure, while the oxide phase was most likely Ta 2 VO 6 through a combined analysis of X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and selected area electron diffraction (SAED). The higher oxygen affinity of Ta and V may explain the preferential formation of their oxide phases based on thermodynamic calculations. Electron backscatter diffraction (EBSD) revealed an average grain size of 6.2 μm. WTaVCr RHEA showed a peak compressive strength of 2997 MPa at room temperature and much higher micro- and nano-hardness than W and other W-based RHEAs in the literature. Their high Rockwell hardness can be retained to at least 1000°C.