Molecular dynamics simulation of atomic diffusion in friction stir spot welded Al to Cu joints

Dissimilar metals joining, especially Aluminum (Al) to copper (Cu), have gained importance in batteries for electric vehicles. Although friction stir spot welding (FSSW) has recently been used dissimilar materials, progress very slow toward understanding the effect of temperature on diffusion condition between two materials with same FCC crystal structure. The thermo-mechanical modeling define trajectory Al and Cu particles at weld interface, but it had a limitation quantified coefficient. Hence, molecular dynamics (MD) study investigate atomic interdiffusion Cu. transmission electron microscopy results are validate MD simulation outcome understand formation dislocations intermetallic compounds. implicated γ-phase (BCC), i.e., Al4Cu9 IMC side. Further, In-situ investigation non-FCC phase FSSW also studied.