Microstructural evolution in W-1%TiC alloy irradiated He ions at high temperatures

Abstract

To investigate the surface damage of a material by He ions, a dispersion-strengthened W-1wt%TiC alloy was irradiated by 5-keV He ions at 773 K, 973 K, and 1173 K up to an ion dose of 1.8 × 1021 He m−2, respectively. No He bubble formation was observed under transmission electron microscopy at any temperature for He doses less than 1.5 × 1020 He m−2. When this dose was exceeded, He bubbles grew and void swelling increased with increasing irradiation doses. Naturally, the growth of He bubbles and the void swelling became more pronounced with increasing irradiation temperatures. Compared to the published data on commercially available pure W, the formation of He bubbles was suppressed by TiC particles in the W–TiC alloy, especially at low doses.