Atomic-scale simulation of nanojoining of Cu-Ag core-shell nanowires

•Simulation results of nanojoining of Cu-Ag core-shell nanowire are discussed.•Cold welding of Cu-Ag core-shell nanowire can introduce few defects.•Welding velocity and remaining deformation in joint can exert great influence.•Cold welding under pressure will cause internal compression of structures. Effective fabrication methods of Cu-Ag core-shell nanowires network are of vital importance for their shining applications in stretchable electronics. In this study, molecular dynamics simulations are performed to study nanojoining of Cu-Ag core-shell nanowires by head-to-head cold welding, along with mechanical properties of obtained welding joints. Results show that Cu-Ag core-shell nanowires can be successfully connected by cold welding with high-efficiency and few defects owing to atomic interaction and diffusion of atoms. What's more, welding velocity and remaining deformation in nanowires will exert significant influence on mechanical properties of joints, including strength and plasticity. It is revealed that cold welding under pressure will somewhat cause internal compression of structures which can be alleviated by following tensile deformation of the two heads if possible. These findings deepen the understanding of nanoscale cold welding and are expected to provide practical reference for the bottom-up fabrication and assembly of Cu-Ag core-shell nanowires network.