Effect on microstructure of Fe80B13Si7 metallic glass irradiated by high intensity pulsed ion beam and He ions

Abstract

Metallic glasses (MGs) are regarded as promising radiation-resistant materials due to their unique long-range disordered structure and abundant free volume. However, temperature sensitivity limits their application in complex irradiation environments, for example, in the fusion environment there are multiple irradiations such as He and strong thermal shock irradiation acting together on the service materials. In this work, the effects of thermal shock and He ions irradiation on the microstructure of Fe80B13Si7 MG were investigated using high intensity pulsed ion beam (HIPIB), He ions and HIPIB + He ions irradiation. It was found that Fe80B13Si7 MG remained amorphous as the main phase structure under all irradiation conditions, and no extensive surface damage occurred even at dose of up to 1.6 × 1018 He2+/cm2. Due to the strong thermal shock effect of HIPIB irradiation, the surface layer of Fe80B13Si7 MG remelted and solidified rapidly, which increased the free volume content. At the same He dose, the HIPIB induced increase in free volume content slightly promoted He bubbles growth and reduced the bubble layer depth, while it had no obvious effect on bubble layer width. As the dose increased, He bubble size and bubble layer width increased significantly. The addition of HIPIB also significantly suppressed the crystallization of Fe80B13Si7 MG induced by He ions irradiation: crystallization occurred within the He bubble layer after 4 × 1017 He2+/cm2 irradiation, while no crystallization was observed after HIPIB + 6 × 1017 He2+/cm2 irradiation. Fe80B13Si7 MG showed good resistance against HIPIB, He ions and HIPIB + He ions irradiation, and perhaps offer some unique advantages in complex irradiation environments.