Theory of Pressure-Induced Rejuvenation and Strain Hardening in Metallic Glasses

We theoretically investigate high-pressure effects on the atomic dynamics of metallic glasses. The theory predicts compression-induced rejuvenation and the resulting strain hardening that have been recently observed in metallic glasses. Structural relaxation under pressure is mainly governed by local cage dynamics. The external pressure restricts the dynamical constraints and slows down the atomic mobility. In addition, the compression induces a rejuvenated metastable state (local minimum) at a higher energy in the free-energy landscape. Thus, compressed metallic glasses can rejuvenate and the corresponding relaxation is reversible. This behavior leads to strain hardening in mechanical deformation experiments. Theoretical predictions agree well with experiments.

Automated summary

The theoretical study predicts compression-induced rejuvenation and strain hardening in metallic glasses, mainly controlled by local cage dynamics. External pressure restricts dynamical constraints and slows down atomic mobility, inducing a rejuvenated metastable state at a higher energy. Consequently, compressed metallic glasses can rejuvenate and exhibit reversible relaxation, leading to strain hardening in mechanical deformation experiments. The theoretical predictions are in good agreement with experimental observations.