Shear-band cavitation determines the shape of the stress-strain curve of metallic glasses

Metallic glasses are known to have a remarkably robust yield strength, admitting Weibull moduli as high for crystalline engineering alloys. However, their postyielding behavior is strongly varying, with large scatter in both flow stress levels and strains at failure. Using x-ray tomography, we reveal how strain-dependent internal evolution of shear-band cavities underlies this unpredictable response. We demonstrate macroscopic strain softening coincides the first detection cavitation. Cavity growth during plastic found follow power law, which yields fractal dimension roughness exponent excellent agreement self-similar surface properties obtained after fracture. These findings microcracking coexists plasticity along part stress-strain curve, rationalizing variability seen metallic glasses.