Indentation creep behaviors of Mg61Cu28Gd11 and (Mg61Cu28Gd11)99.5Sb0.5 bulk metallic glasses at room temperature

The room temperature creep behaviors of Mg61Cu28Gd11 and (Mg61Cu28Gd11)99.5Sb0.5 bulk metallic glasses (BMGs) were revealed by means of nanoindentation technique. The creep mechanism was explored by characterization of creep rate sensitivity, creep compliance and retardation spectra. The results showed that the experimental creep curves could be well described by a generalized Kelvin model. The low creep rate sensitivity of both Mg-based BMGs indicated that their room temperature creep was dominated by localized shear flow. In addition, the (Mg61Cu28Gd11)99.5Sb0.5 glassy alloy exhibited lower creep rate sensitivity, creep compliance and milder retardation peak, indicating its higher creep-resistance and less relaxed state. Furthermore, the creep retardation spectrum consisted of two relatively separated peaks with the well defined characteristic relaxation times.