Stress-induced gradient rejuvenation framework and memory effect in a metallic glass

Abstract

Rejuvenation of metallic glasses (MGs) brings them in higher-energy states, which improves their mechanical properties. However, how to rejuvenate MGs through a fast and simple approach is still a challenge. In the present work, a nonuniform structure consisting of a center-relaxation region surrounded by an edge-gradient-rejuvenation framework was created in a Zr-based bulk metallic glass (BMG) by lateral elastostatic preloading. Such a nonuniform structure greatly suppresses the rapid propagation of shear bands and has the potential to overcome the inverted relationship between strength and plasticity. More interestingly, we found a stress-induced memory effect, viz., the recovery of relaxation enthalpy during elastostatic loading, which is quite different from the thermal-induced memory effect in previous works. This indicates a certain degree of equivalence between stress and temperature in the dynamics of MGs.