Clinch-resistance spot welding of galvanized mild steel to 5083 Al alloy

A novel clinch-resistance spot welding method of dissimilar materials was presented. A group of punch-die electrodes was used to weld 1-mm 5083 Al alloy and 1-mm galvanized steel sheets. Microstructure and mechanical properties of the welded joints obtained with punch-die electrodes were studied. Stress is analyzed by numerical simulation, and the tensile shear strength distribution under different welding parameters is analyzed using artificial neural network. A cup section is formed after welding, which results in 3D connection of the bonding interface. Stress concentration on the steel/Al contact surface locates on the connection between the punch tip and die tip. The melt zone is mainly formed at the nugget edge, and a relatively small melting area is generated at the central area on the Al side. The maximum failure load can be increased to 4.5 kN. The range of parameters for obtaining high strength is relatively wide in clinch-resistance spot welding, and the interaction of current and time has a significant effect on the strength.