Nanoindentation Analysis of Time-Dependent Deformation in Cu-Zr Bulk Metallic Glasses

Abstract

The time-dependent deformation of bulk metallic glasses (BMGs) has been often analyzed using instrumented indentation test. In this study, we attempted to systematically investigate the time-dependent deformation behavio-ur of Cu-Zr binary BMGs at room temperature through nanoindentation experiments. Examined are three kinds of the BMGs having different amount of initial free volume; as-cast Cu50Zr50, structurally-relaxed Cu50Zr50, and as-cast Cu65Zr35. BMGs In nanoindentation creep tests, the load was increased up to the peak load of 50 mN under a verity of loading rate (0.1 ~ 2.5 mN/s) and then hold for 400s. Results are discussed in terms of the influence of free volume on the time-dependent behavior and the viscoelastic properties of the BMGs.