Study of irradiation damage induced by He2+ ion irradiation in Ni62Ta38 metallic glass and W metal

Metallic glasses are considered to possess good resistant against irradiation due to their inherent structural long-range disorder and a lack of grain boundaries. The He2+ with an energy of 300 keV was used to irradiate Ni62Ta38 binary metallic glass to investigate its resistance against the irradiation, and the irradiated behaviour of the metallic glass was compared with that of W metal. The irradiation fluence range over 2.0 × 1017 ions/cm2-1.6 × 1018 ions/cm2. The TEM results show that nanocrystals of μ-NiTa phase and Ni2Ta phase appeared in Ni62Ta38 metallic glass under the irradiation fluence of 1.6 × 1018 ions/cm2. The SEM results show that the surfaces of Ni62Ta38 metallic glasses maintained flat and smooth, whereas a large area of blisters with peeling formed on the surface of W metal at the irradiation fluence of 1.0 × 1018 ions/cm2. It indicates that the critical irradiation fluence of surface breakage of the Ni62Ta38 metallic glass is higher than that of W metal. After the irradiation, stress was generated in the surface layer of W metal, leading to the increase of the hardness of W metal.