Molecular dynamics study of the effect of alloying elements and imperfections on linear friction welding of Cu and Ni metals

There are many physical phenomena and properties associated with diffusion in linear friction welding (LFW) process. Many of these phenomena are not observable by known and conventional methods. The molecular dynamics (MD) is an advantageous and practical method to study the diffusion process and atomic behavior of welded materials. In the current research, we used MD simulations to model the LFW process between copper and nickel metals. The effect of defects in the structures and also the addition of alloying elements to the copper structure was also studied. Our findings revealed that the surface and subsurface imperfections in the copper structure were gradually eliminated in the friction stage. In contrast, these imperfections in nickel structure disappeared in the forging stage. Also, we showed that adding alloying elements to copper structure leads to an increase in the amount of the mean square displacement (MSD) of the atoms and the diffusion coefficient in copper. [Display omitted] •Diffusion coefficient of Ni and Cu atoms during FW is studied using MD method.•Adding Al & Fe atoms to Cu increases displacement and diffusion coefficient of atoms.•Imperfections in the Cu structure are gradually eliminated in the friction stage.•Imperfections in the Ni structure are eliminated in the forging stage.