Thermal stability and evolution of microstructures induced by He irradiation in W-TiC alloys

Dispersion-strengthened W alloys, W-1%TiC and W-2%TiC, were fabricated by spark plasma sintering (SPS). The thermal stabilities of the secondary-phase TiC particles and microstructures in the W alloys during thermal treatments from 100 to 1000 °C were investigated by positron annihilation techniques. The TiC particles were stable in both W-TiC alloys during the annealing process. Both alloys were irradiated by 5-keV He ions at 900 °C-1.8 × 1021 He/m2. Compared with commercially available pure W, the formation of He bubbles was suppressed by the TiC particles in the W-TiC alloys, and the extent of suppression increased as the amount of added TiC was increased.