Ductile-to-brittle transition criterion of metallic glasses

In principle, the ductile-to-brittle transition (DBT) of metallic glasses may be dominated by the competition between shearing and cracking at different stress states. In response to this issue, we propose a new and concise criterion for DBT, named as the shearing-cracking (S-C) criterion, which can accurately predict the critical transition behaviors in metallic glasses induced by variations in both stress state (extrinsic factor) and Poisson's ratio (intrinsic factor). Furthermore, the S-C criterion provides a reasonable explanation for the peculiar phenomenon in metallic glasses that there are rare experimental cases of tensile fracture angle within the range of ${60}^{\circ }$ to ${90}^{\circ }$. Importantly, the S-C criterion offers theoretical guidance for toughness enhancement in metallic glasses from both intrinsic and extrinsic factors, thus facilitating the advancement of engineering applications involving metallic glasses.