A nanoindentation study of Ti-based high entropy bulk metallic glasses at elevated temperatures

Nanoindentation was used to explore the mechanical properties of high entropy bulk metallic glasses (HE-BMGs) from room to elevated temperatures. Two Ti-based HE-BMGs and two conventional counterparts were investigated. Below the glass transition temperature, softening is observed for conventional BMGs with increasing temperature, whereas hardness keeps almost unchanged for HE-BMGs. The resistance to thermal softening might originate from the highly stable high entropy structure, which retards atomic diffusion and rearrangement for shear transformation. Above the glass transition temperature, HE-BMGs show quite low hardness and pronounced creep deformation, suggesting that high entropy may facilitate fast diffusion in the viscous flow.