A prospect of using ternary W-5 wt%V-5 wt%Ta alloy manufactured by mechanical alloying and spark plasma sintering as plasma-facing material

• Ternary W alloy W-5 V-5Ta was manufactured by MA and SPS. • W-5 V-5Ta has the ultrafine grain size and a single-phase BCC structure. • W-5 V-5Ta has better mechanical properties and He+ irradiation resistance. • The contribution of strengthening mechanisms was estimated by Hull-Petch formula. • The good irradiation resistance is caused by ultrafine grain and high strength. For ensuring W employed as the armor of the divertor component in International Thermonuclear Experimental Reactor, a ternary W alloy W-5 wt%V-5 wt%Ta was manufactured by mechanical alloying and spark plasma sintering. (V, Ta)-enriched fine grains and W-enriched grains were observed in W-5 wt%V-5 wt%Ta with a single-phase body centered cubic structure. W-5 wt%V-5 wt%Ta has an ultrafine grain size, and higher relative density, microhardness, and strength than the pure W. The strenghening mechanisms were estimated, and the results indicate that grain refinement, densification, and solid solution play the main, secondary and small strengthening roles, respectively. W-5 wt%V-5 wt%Ta has a good irradiation resistance. This good irradiation resistance has a relationship with the ultrafine grains as well as higher compressive and tensile strength of W-5 wt%V-5 wt%Ta. The damage of irradiation was quantitatively analyzed by the 3D laser scanning confocal microscope. This research work suggests that W-5 wt%V-5 wt%Ta can be applied as a potential plasma-facing material.