Nanostructured TiC dispersion-strengthened tungsten composite with remarkably improved He ion irradiation resistance

Improving the irradiation resistance of W alloys is vital to their application of plasma facing materials in future fusion reactors. In this work, quasi-spherical tungsten nanoparticles synthesized by thermal plasma were mixed with nanosized TiC to sinter nanostructured TiC dispersion-strengthened tungsten alloy. As-obtained W-TiC composite exhibited high relative density of 99.14% with suppressed grain size of about 1.12 mu m, together with well-dispersed TiC with size 50-100 nm into W grains. More importantly, semi-coherent W/TiC interface with diffusion layer of about 25 nm was formed, which highlights the tight connection between W and TiC. Furthermore, He ions irradiation results indicated that W-TiC composite exhibited excellent irradiation resistance with a damage depth of about 9.53 mu m, which is much lower than 18.26 mu m of pure W. Mechanism investigation indicated that the remarkably improved He ion irradiation resistance was attributed to the efficient capture and annihilation of irradiation-induced defects by grain boundaries and phase interfaces.