Steady-state serrated deformation of metallic glass during indentation

Using an exponential load profile with a Berkovich tip, the strain bursts produced during nanoindentation of a (Cu55Mg33Y12)–Be bulk metallic glass are found to reach a steady state, in which the hardness becomes constant, the displacement jumps normalized by the indent depth approach a constant range 1.4 ± 1.2% and correspond to a reduction in hardness of 2.8 ± 2.4%, and the inter-burst duration multiplied by the strain rate approaches a constant range 1.8±0.61.8±0.6%. This steady-state behavior is insensitive to the strain rate used.