Mechanical annealing in the homogeneous deformation of bulk metallic glass under elastostatic compression

Elastostatic compression test on Zr60.14Cu22.31Fe4.85Al9.7Ag3 bulk metallic glass (BMG) is conducted at 90% of yielding strength at room temperature. Homogeneous deformation with 0.48% plastic strain is achieved after holding for 5 days. The deformed BMG shows decreased relaxation enthalpy and increased critical shear stress, yield strength and density under elastostatic compression, namely a mechanical annealing effect. This phenomenon is rationalized in terms of the atomic level stress theory and the coalescence of negative and positive free volume.