Mechanical characteristics of friction-welded copper-silver junction with iron tip via molecular dynamics simulation: influence of initial temperature

Abstract This study employed molecular dynamics simulations to investigate the atomistic response of a copper–silver interface under simplified friction-welding-inspired loading. The mechanical response of the tool-modified copper–silver interface was analyzed, focusing on the influence of the initial temperature (300–400 K). The research methodology was divided into two phases: first, the physical stability of modeled samples was assessed at an initial temperature of 300 K by monitoring key physical parameters, such as kinetic and total energy. Subsequently, simplified friction-welding-inspired loading was applied to the equilibrated sample, followed by mechanical deformation to evaluate the resulting interfacial response. This approach enabled a detailed analysis of temperature-dependent mechanical characteristics, including stress–strain behavior, radial distribution function, interaction energy, mean square displacement, ultimate strength, and Young's modulus. Results show that increasing temperature increases thermal energy, weakening the interatomic bonds between copper and silver atoms and thereby reducing the ultimate strength and stiffness of the tool-modified interface. Specifically, the ultimate strength decreased from 1490.27 MPa to 1348.88 MPa as the temperature increased from 300 to 400 K, while Young's modulus decreased correspondingly. This study provides atomistic insights into how initial temperature affects the mechanical response of a copper–silver interface under simplified friction-welding-inspired conditions.