Resistance spot welding of aluminum alloy to steel with transition material - From process to performance - Part I: Experimental study

This paper summarizes our work to date on resistance spot welding of aluminum alloy to steel, from process development to performance evaluation. Since aluminum alloys and steel cannot be readily fusion welded together due to their drastically different thermal physical properties, a cold-rolled clad material was introduced as a transition to aid the resistance welding process. The optimal welding parameters and electrode selections were established using experimental approaches. The welded samples' mechanical behaviors were then evaluated using static and dynamic weld strength tests as well as cyclic fatigue tests. The weld strength, failure mode, and fatigue life were then compared with self-piercing rivets of the same dissimilar metals combination. Statistical analyses were also performed to analyze the effects of different failure modes on samples' peak strength and energy absorption.