Effect of Ti and TiC alloyants on the mechanical properties of W–based armour materials

The main requirements of tungsten materials for structural divertor applications comprise properties like high thermal conductivity, high-temperature strength and stability, high recrystallization temperature, and enough ductility for an operation period of about two years under massive neutron load [1]. However, the mechanical properties of tungsten commercial products are still one of the main concerns for their use in structural armour applications. With the aim of improving this aspect, two W/Ti based products are presented in this paper: (1) a W-Ti alloy with a Ti solid solution and (2) an UFG microstructure product with TiC dispersed particles; both with the aim of obtaining a suitable fusion armour material with enhanced properties, especially at very high temperatures when pure tungsten suffers strong thermal degradation. It has been reported that strength and recrystallization control can be improved with dispersed TiC particles which inhibits the grain growth. Furthermore, both flexural strength and fracture toughness were twice and even three times higher than the ones observed for our reference pure tungsten produced by the same group and technique, which is, indeed, a great success. However, the intrinsic brittleness of tungsten cannot be enhanced by particle dispersion or solid solution with Ti. On the contrary, intergranular rupture is enhanced even more, and the DBTT is even higher than that of pure W.