Nanostructured designs for extreme strain hardening of metallic glasses

Abstract

The absence of ductility has historically limited the practical applications of metallic glasses. Despite extensive research over many years, a sophisticated and effective solution remains elusive. Inspired by the design of fractal nanostructures, we propose an enhanced nanostructure design method that effectively mitigates the complexity of engineering applications. Through simulation studies, we demonstrate that by optimizing nanostructures, metallic glasses exhibit substantial tensile ductility and strain hardening. This enhancement is attributed to the synergistic effect of multiple nanobranches, which collectively contribute to the deformation process, impeding the formation of shear bands and inducing homogeneous deformation of the metallic glass, thereby altering its conventional deformation mode. To achieve enhanced plasticity and substantial strain hardening, it is essential to maintain a low overall connectivity of the nanostructured metallic glass, thereby preventing the formation of shear bands throughout the sample.