Effects of joint type on microstructure and mechanical properties of Al/brass joint welded by thermo-compensated resistance spot welding

The process of thermo-compensated resistance spot welding for aluminum alloy 6061-T6 and alpha brass H70 was studied by using different lap joint design. The difference of microstructures and mechanical properties of Al/Brass dissimilar joints welded by two kinds of joint design was compared. The results showed that aluminum alloy and brass can be welded at lower current by using thermo-compensated resistance spot welding. When the thermal compensation coupon was set at Al side, the tensile shear load of the joint was higher in which the nugget consisted of fine equiaxed α-Al grains. When the thermal compensation coupon was set at brass side, the tensile shear load of the joint was lower, but ductile fracture characteristic was showed and the nugget consisted of lath-shaped Cu-Al intermetallic compound.