The prominent combination of ultrahigh strength and superior tensile plasticity in Cu–Zr nanoglass connected by oxide interfaces : a molecular dynamics study

Abstract

A novel Cu–Zr nanoglass consisting of glassy nano-cells connected by oxide interfaces is proposed. Compared to conventional nanoglasses, the novel oxide-connected nanoglass presents ultrahigh tensile strength and superior tensile plasticity at ambient temperature. Subjected to tensile loading, the oxide interfaces are found to promote the nucleation of shear transformation zones (STZs) due to the existence of excess free volume. Meanwhile, the strong bonding between metallic and oxygen atoms in the oxide interface makes it difficult for STZs to propagate through. Thus, the STZs are effectively proliferated and confined inside the cell interior without any mature shear band (SB) formed. The results provide new ideas for toughening metallic glasses with a decent combination of plasticity and strength, thus making it possible to overcome the longstanding strength-ductility trade-off dilemma.