Structural rejuvenation and relaxation of a metallic glass induced by ion irradiation

The influence of ion irradiation on structural rejuvenation and relaxation in a Zr-based metallic glass (MG) is investiagted. The MG can be structurally rejuvenated with increasing irradiation dosage from 0 to 3 dpa, which reflects in increased activation volumes of shear-transformation zones. However, structural relaxation dominates at a high irradiation dosage (4 dpa) resulting in higher hardness. The anelastic-relaxation processes in the irradiated MG can be understood in terms of the coordination mechanism of the deformation modes associated with free volume. Ion irradiation appears to be a promising and effective way to modify MGs and to, thus, manipulate plastic flow.