The effect of pressure-promoted thermal rejuvenation on the fracture energy of metallic glasses

Despite that the pressure-promoted thermal rejuvenation is a promising remedy for the plasticity enhancement of metallic glasses (MGs), there has been so far little studies of the effect of rejuvenation on the fracture toughness of MGs. Herein, molecular dynamic simulations are performed to study the influence of annealing pressure (Pa) on the fracture energy (G) of rejuvenated MGs. Our results manifest that the G increases at first and then decreases with Pa, showing a two-stage behavior. The increase of G is attributed to the improved plasticity but marginal change of strength, while the decrease of G is caused by the significant reduction of strength. Another key finding is that the improved plasticity arises from the more homogeneous activation of shear transformation zones due to its lower activation energy in the high-energy rejuvenated state. The present study establishes the influence of Pa on G based on the internal structure analyses.