Microstructure and Mechanical Properties of Al/Ti Dissimilar welded Joints Fabricated by Resistance Spot Welding with Process Tapes

This study investigates the microstructure and mechanical properties of dissimilar metal joints between 6061 aluminum alloy and TC4 titanium alloy, fabricated using resistance spot welding with belt-assisted process. The influence of welding parameters, such as welding current, welding time, and electrode pressure, on the weld joint's morphology, nugget size, and fracture mode is systematically analyzed. The results show that the Al/Ti spot weld joints exhibit a typical fusion brazing characteristic, with TiAl ₃ and Ti ₂ Al ₅ intermetallic compounds formed at the interface. Two fracture modes were observed: button fracture and interfacial fracture. The tensile shear force first increases and then decreases with increasing welding parameters, reaching a maximum of 7.02 kN. This study provides a theoretical foundation and technical support for the welding of thin-walled Al/Ti dissimilar metal structures.