Tensile deformation of metallic glass and shape memory alloy nanolaminates

Mechanical deformation of Cu 50 Zr 50 metallic glasses (MGs) with CuZr B2 layers was explored using tensile tests under iso-strain and iso-stress conditions using molecular dynamics simulations. Atomic structure identification was conducted through machine learning techniques, enabling a distinct examination of the deformation exhibited by each phase. Our results revealed early -stage plasticity driven primarily by shear transformation zones at the amorphous/crystalline interface, rather than shear band formation and propagation observed in the monolithic MG, leading to nanolaminates with enhanced strength. Furthermore, under iso-strain deformation, B2 layers underwent martensitic transformation promoted by the nucleation of voids. However, void growth quickly supersedes these effects under both iso-strain and iso-stress conditions, culminating in sample fracture. In summary, this work advances our understanding of amorphous/crystalline nanolaminates, providing valuable insights into their mechanical complexities.