Nanowelding of nickel and copper investigated using quasi-continuum simulations

Abstract

The effects of contact interference, crystal orientation, and material type on the cold nanowelding mechanism and mechanics are studied using quasi-continuum simulations. These effects are investigated in terms of atomic trajectories, strain distribution, and the stress–strain curve. The simulation results show that welding using a contact interference of 0 nm leads to the formation of the fewest defects inside the material during cold welding, and that the number of defects increases with increasing contact interference. For the Ni–Ni welding pair, welding using a contact interference of 0 nm with the structural orientation [110] versus [001] has the largest ultimate strength and longest elongation during tensile testing due to the formation of fewer defects during welding. The welding quality obtained with the Ni–Ni welding pair is higher than that obtained with Ni–Cu and Cu–Cu welding pairs. During the tensile deformation process, dislocations nucleate from the free surface, propagate along the close-packed plane, and then terminate at the other free surface.