Atomistic Simulation on the Mechanical Properties of Diffusion Bonded Zr-Cu Metallic Glasses with Oxidized Interfaces

A novel welding technique of diffusion bonding for Zr-Cu metallic glass with pre-oxidized surfaces is proposed in this study, which is systematically investigated by molecular dynamics (MD) simulation. Compared with the conventional welding technique, the diffusion bonding process can be well implemented below the crystallization temperature of metallic glass. The obtained structure possesses glass–glass interfaces (GGIs) similar with those in nano-glasses. As revealed by MD simulation, the diffusion bonded metallic glasses possess enhanced mechanical strength and ductility that generally do not exist in nano-glasses and their bulk metallic glass counterparts. The GGIs are found to hinder the propagation of shear bands, where there is strong bonding between Zr and O and the segregated Cu and ZrO₂ clusters could induce extra plasticity. The results demonstrate that the diffusion bonding of metallic glass with pre-oxidized surfaces could provide an alternative approach in solving the longstanding issue of size limitation on metallic glasses.