Indentation creep study on a Zr-based bulk metallic glass containing nano-quasicrystals

The effect of crystallization on the creep behavior of a Zr-based bulk metallic glass (BMG) with the composition of Zr44Ti11Cu10Ni10Be25 (at.%) was studied by indentation technique. The crystallization process was studied by isothermal annealing in a differential scanning calorimeter at three different temperatures above the glass transition temperature (677, 682 and 687 K). Two exothermic peaks are detected, the first one corresponds to the formation of a quasicrystalline phase. Indentation creep tests were carried out isothermally at the same three temperatures for studying the correlation between the amount of quasicrystalline phase and the creep behavior. A simple relationship between the viscosity and the crystalline phase fraction was found and the activation energy was found to decrease with the progress of crystallization.