Molecular dynamics simulation of the effect of surface roughness and pore on linear friction welding between Ni and Al

Atomic model of Ni–Al linear friction welding is established by molecular dynamics simulation. The effect of surface roughness on linear friction welding and the rules of pore closure are investigated. The simulations results show that rough surfaces are gradually flattened during the friction process. The rough surface of the harder material (Ni) may influence the final structure of the weld. Pores near the interface is closed after linear friction welding. Pore closure in Al slab occurs in friction process by atom diffusion, while it takes place in Ni slab in forging stage mainly by deformation of the interface.