Study on resistance spot brazing process and joint performance of pure aluminum 1060 / galvanized steel

Resistance spot brazing was used to perform the lap test of pure aluminum 1060 and SGCC hot-dip galvanized steel plate, the joint interface structure was studied, and the mechanical properties of the joint were tested. The results show that the aluminum-silicon (Al-Si) alloy solder used in the test has good wetting, and an intermetallic compound with a double-layer structure and uneven thickness is produced at the welded joint interface after welding. The thickness is <10 μm. The welding current is at 7.8 kA, the tensile shear load of the joint reaches a peak value of about 4.72 kN. Under the same process parameters, the tensile shear load of the resistance spot brazed joint is significantly higher than that of the spot welded joint. The joint fracture mostly occurs on the aluminum plate side, and mainly at the heat-affected zone and not at the welding point.It indicates that the quality of the spot brazed joint is good, but due to the local "unbrazed" defect on the aluminum side interface of the weld, tensile stress will occur at the weld interface and the stress effect on the intermetallic compound. It is easy to produce cracks.