Behavior of high resistance to He2+ induced irradiation damage in metallic glass

This study details the irradiation of various metallic glasses ((Cu47Zr45Al8)98.5Y1.5, Zr64Cu17.8Ni10.7Al7.5, Co61.2B26.2Si7.8Ta4.8) and metallic W using He2+ ions with an energy of 500 keV at irradiation fluences of 2 × 1017, 1 × 1018 and 2 × 1018 ions/cm2 to investigate the radiation-resistant properties of these metallic glasses compared to the conventional irradiation-resistant material W. These three metallic glasses were able to maintain an amorphous state during these irradiation fluences. There was no significant irradiation damage at the low irradiation fluence. When the irradiation fluence was increased to 2 × 1018 ions/cm2, a damage layer appeared up to a distance corresponding to the range of the ions away from the surfaces of the Cu- and Zr-based metallic glasses without any visible damage on the surface. Significant surface stripping damage appeared in the Co-based metallic glass. Relatively speaking, surface layer peeling appeared in metallic W along the crystal boundary at a fluence of 1 × 1018 ions/cm2. When the fluence was increased to 2 × 1018 ions/cm2, multilayer peeling, stripping, etc. appeared. The roughness of the Cu- and Zr-based metallic glass showed further smoothing with increasing fluence, while the opposite occurred in the Co-based metallic glass. Within the wavelength range of 400-1700 nm, after irradiation of He2+ at a fluence of 1 × 1018 ions/cm2, the reflectance of the Cu-based and Co-based metallic glasses were decreased by only 17% and 13%, respectively.