Structural Rejuvenation in Metallic Glass by High-Pressure Torsion(Research)

Abstract

Effect of high-pressure torsion (HPT) deformation on mechanical properties was investigated on Zr_<50>Cu_<40>Al_<10> bulk metallic glass by nanoindentation. HPT deformation resulted in the structural rejuvenation and pronounced decreases in hardness and elastic modulus. These changes were also accompanied by the transition of deformation mode from localized shear band formation to homogeneous deformation, as well as by a decrease in the frequency of pop-ins. Annealing of the deformed BMG led to the restoration of the localized deformation, hardness and elastic modulus; thus the transition is reversible. The observed reversible transition can be attributed to a change in the local atomic environment in the rejuvenated volume and the relaxed one.