Hidden order in the fracture surface morphology of metallic glasses

We report the fractal nature of dimple structures on the fracture surface of various metallic glasses (MGs) with significantly different mechanical properties. The analyzed fractal dimension increments of MGs lie in a narrow range of 0.6–0.8. The results indicate that the MGs with marked differences in plasticity and toughness may have a unified local softening mechanism and similar nonlinear plastic behavior in front of the crack tip during fracture. We present a physical picture for the dimple structure formation from the plastic zone in front of the crack tip. The evolution of the plastic zone from the interaction of the shear transformation zones is theoretically modeled as a stochastic process far from thermodynamic equilibrium, and the model can capture the formation and fractal nature of the dimple structures on the fracture surface of metallic glasses.