Electrically assisted solid-state pressure welding process of SS 316 sheet metals

Physical experiments were conducted to study the effect of electric current on the shear strength of pressure-welded SS 316 sheet metals. Through experiments, it is found the shear strength first increases with the welding pressure, then decreases due to the excessive thinning. Higher current density leads to larger maximum shear strength. The numerical simulations of welding process were also carried out to explore the influence of current density on the bond formation: using the critical stress as the indicator of joining, the bond area is found to increase significantly with the current density from 5 Å/mm2 to 20 Å/mm2 when the thickness reduction is below 80%. The welding force required for successful joining also decreases with the increase of current density. Based on the simulations, the shear strength is further predicted by modeling the joining behavior and the results are corroborated and verified by experiments.