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. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.