Magnesium alloy AZ31B and titanium TA2 were welded by resistance spot welding technology employing an interlayer of aluminum foil and asymmetric electrodes. The microstructure of the joint was observed, with an analysis conducted on the impact of welding current and welding time on the tensile shear load of the joint. During the welding process, the aluminum interlayer melted and blended with the molten magnesium alloy, leading to the formation of a eutectic layer consisting of Mg17Al12 and (Mg) in close proximity to the welding interface. As the increasing of welding current or the extending of welding time, there was an initial increase followed by a slight decrease in the tensile shear load of the AZ31B/TA2 joint. At a welding current of 16 kA, the tensile shear load of the joint achieved the maximum, which was approximately 6.48 kN. The findings suggest that it is effective to use an aluminum foil as an intermediary to regulate the metallurgical reaction at the interface and utilize nonsymmetrical electrodes for thermal compensation in the resistance spot welding between titanium and a magnesium alloy.

Resistance spot welding was performed to join a 2 mm thick TA2 titanium plate and Q235 steel plate using nickel foil with thicknesses of 0.02 mm, 0.04 mm, and 0.06 mm as interlayers. The microstructure of the nugget zone and the interface region of the joint were systematically observed and analyzed, and the tensile shear-bearing capacity of the joint was evaluated. As the welding current increased, the tensile shear load of the joint exhibited a trend of initially increasing and subsequently decreasing. When the welding current was 8 kA, the tensile shear load of the joints with an interlayer of 0.04 mm thickness reached a maximum value of 8.02 kN. The results indicate that employing a reduced welding current can effectively prevent the mixing of nuggets on both sides of the titanium and steel interface. This ensures that the intermetallic compounds formed in the interface region are confined to the Ti-Ni series, which is crucial for enhancing the tensile shear load of the joint.

Resistance spot welding was performed to join 2 mm thick TA2 titanium plate and Q235 steel plate using nickel foil with thicknesses of 0.02 mm, 0.04 mm, and 0.06 mm as interlayers. The microstructure of the nugget zone and the interface region of the joint was systematically observed and analyzed, and the tensile shear bearing capacity of the joint was evaluated. As the welding current increased, the tensile shear load of the joint exhibited a trend of initially increasing and subsequently decreasing. When the welding current was 8 kA, the tensile shear load of the joints with the interlayer of 0.04 mm thickness reached the maximum of 8.02 kN. The results indicate that employing a reduced welding current can effectively prevent the mixing of nuggets on both sides of the titanium and steel interface. This ensures that the intermetallic compounds formed in the interface region are confined to the Ti-Ni series, which is crucial for enhancing the tensile shear load of the joint.

A 1060 commercial-purity aluminum and T2 pure copper plates with a thickness of 2 mm were welded by using resistance element welding with an aluminum rivet and auxiliary gasket. The interfacial microstructure was analyzed, and the tensile shear load of the joint was tested. In the joint welded, a layer of Al2Cu adjacent to the copper and the eutectic structure of Al2Cu + (Al) near the nugget region were formed at the interface of Al/Cu. The tensile shear load of the joint increased first and then decreased with the increase of welding current, and it reached the maximum of 2.24 kN when the welding current was 26 kA. The results reveal that the application of the auxiliary gasket not only promote the thickening of the nugget, but also achieve the joining between the rivet leg and the upper plate when resistance element welding of Al/Cu is performed.