Study on the time-dependent deformation of Cu-Zr binary amorphous alloys

Abstract

In this study, we attempted to systematically investigate the viscoelastic and viscoplastic behavior 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. In nanoindentation creep tests, the load was increased up to 50 mN under a verity of loading rate (0.1 ~ 2.5 mN/s) and then hold for 400s. Subsequently, 1% of maximum indentation load (0.5 mN) was hold after unloading procedures (0.1 ~ 2.5 mN/s) during 400s. Results are discussed in terms of the influences of initial free volume and loading/unloading rate on the creep and recovery of glasses.