Thermomechanical Behavior of Cu50Hf41.5Al8.5 Bulk Metallic Glass after Sustained Elastic Deformation

Abstract

Thermomechanical analysis (TMA) was conducted in a temperature modulated mode to analyze the effect of static and dynamic elastic compression on a Cu 50 Hf 41.5 Al 8.5 bulk metallic glass. The nonreversible length changes clearly demonstrate that the elastic loading affects the thermomechanical behavior of the metallic glass. A sustained static elastic compressive load increases the relative length decrease, while a dynamic elastic load to the same maximum load and for the same time reduces the length decrease. A preliminary interpretation suggests that the static compression raises the defect of free volume level, but the dynamic compression mimics annealing and reduces the free volume level. Elastic compression thus emerges as a novel tool to control the free volume level of metallic glasses.