Development and Testing of Dispersion-Strengthened Tungsten Alloys via Spark Plasma Sinterin

Tungsten (W) is a common plasma-facing component (PFC) material in the divertor region of tokamak fusion devices due to its high melting point and high sputter threshold [1]. However, W is intrinsically brittle and is further embrittled under neutron irradiation, and the low recrystallization temperature pose complications in fusion environments [1,2]. More ductile W alloys, such as dispersion-strengthened tungsten are being developed. In this work, W samples are processed via spark plasma sintering (SPS) with TiC, ZrC, and TaC dispersoids alloyed from 0.5 to 10 weight {\%}. SPS is a powder compaction technique that provides high pressure and heating rates via electrical current, allowing for a lower final temperature and hold time for compaction [3]. Initial testing of material properties, smicrostructure, and composition of specimens will be presented. Deuterium and helium irradiations have been performed in IGNIS, a multi-functional, \textit{in-situ }irradiation and characterization facility at the University of Illinois. High-flux, low-energy exposures at the Magnum-PSI facility at DIFFER exposed samples to a D fluence of 1x10$^{\mathrm{26\thinspace }}$cm$^{\mathrm{-2\thinspace }}$and He fluence of 1x10$^{\mathrm{25}}$-1x10$^{\mathrm{26}}$ cm$^{\mathrm{-2}}$ at temperatures of 300-1000 C. \textit{In-situ} chemistry changes via XPS and \textit{ex-situ} morphology changes via SEM will be studied. [1] D. Naujoks, et al. \textit{Nucl. ~Fusion}. Vol 36,~No. 6 (1996) [2] S.J. Zinkle, et al. \textit{Annu. Rev. Mater. Res.} 2014. 44:241--67. [3] J.R. Groza, et al. \textit{Mat. Sci. and Eng. }A287 (2000) 171-177. Work supported by US DOE Contract DE-SC0014267