Healing effect of sub-T_g thermal cycling on a Cu₆₄Zr₃₆ metallic glass: a molecular dynamics simulation study

The healing effect of sub-T_g thermal cycling on the mechanical behaviour of CuZr metallic glass with pre-existing plastic deformation has been investigated using molecular dynamics simulations. Initially, a uniaxial tensile load was applied to induce strains of 5%, 10%, 15% and 20%. Subsequently, as-cast and deformed samples were subjected to thermal cycles below the glass transition temperature T_g. The potential energy and structural changes at the atomic level during deformation and thermal cycling were monitored. Additional tensile tests were conducted on as-cast, deformed, and thermally cycled samples to see the healing effect of thermal treatment. Results show that during deformation, the potential energy increases while the content of icosahedral drops. While these trends are reversed during the subsequent thermal cycles. Tensile tests reveal that the tensile strength drops with increasing level of initial deformation. Contrarily, thermal cycles restore the strength, resulting in a healing effect. Furthermore, deformation degrades the mechanical properties of materials in all directions, regardless of the applied loading direction that induces deformation.