To elucidate the influence mechanism of structural rejuvenation on the corrosion resistance of bulk amorphous alloys, Zr_52.5Cu_17.9Al₁₀Ni_14.6Ti₅ bulk amorphous alloy is prepared by arc melting combined with copper mold suction casting. The effect of the initial structural state on the structural rejuvenation and corresponding corrosion resistance of the alloy is systematically investigated. The results indicate that sub-T_g annealing significantly enhances the corrosion resistance by promoting structural relaxation and homogenization. For instance, after annealing at 0.9T_g for 1 h, the corrosion current density is decreased by approximately 57% compared to the as-cast state. In contrast, structural rejuvenation, as the reverse process of annealing, deteriorates the corrosion resistance by exacerbating structural heterogeneity. Specifically, after thermal cycling of the sample annealed at 0.7T_g, the corrosion current density is increased by 73.22%, and the pitting potential shifted negatively by approximately 25 mV. In addition, the effect of structural rejuvenation on the deterioration of corrosion resistance strongly depends on the initial structure of the bulk amorphous alloys. This work provides an important scientific basis for understanding of the correlation between structural state and corrosion resistance of bulk amorphous alloys.

Both the large elasticity and high strength make metallic glasses (MGs) an ideal model for studying the strength theory of high-strength materials. But the poor plasticity greatly limits the application of MGs. During the past few decades, many researchers have tried to solve this catastrophic fracture by developing new components, structural rejuvenation or surface regulation. Although some enhancements of plasticity have been achieved, the mechanism of brittle fracture of MGs is still not clear. Generally, study on the evolution of fracture features is usually an effective method to uncover the failure mechanism of metal materials. Compared with crystalline alloys, MGs exhibit extremely rich and complex fracture behaviors, one typical of which is that the fracture morphologies can present a cross-scale diversity from micro-scale vein patterns, sub-micron dimples to nano-scale periodic corrugations. In this letter, the recently studies on the evolution of fracture features of MGs have been summarized and some unsolved issues associated with the fractural morphologies of MGs are proposed.