Rejuvenation mechanism in metallic glasses induced by strain cyclic loading

Rejuvenation, contrary to aging process, can enhance mechanical properties in metallic glasses (MGs), but the related atomic scale mechanisms remain elusive. In this work, rejuvenation in a Cu₄₅Zr₄₅Al₁₀ glass is generated through strain cyclic loading in a molecular dynamics simulation, in order to explore the involved microscopic features. The results find out that cyclic loading significantly regulates the energy state and the dynamical relaxation behavior of the metallic glass. Rejuvenation induced by cycling increases the dynamic heterogeneity and changes local structures in the whole system, not only in soft spots but also in rigid regions. During simulated dynamical mechanical spectroscopy non-activated atoms correspond to local-five-symmetry, but activated atoms exhibit structures with features that still need to be investigated. Our study reveals the microscopic dynamic and structural features of rejuvenation via cyclic loading in MGs, which can provide a theoretical basis for designing methods to control the properties of these materials.