Study on magnetic pulse spot welding process for AA5052 aluminium alloy

Magnetic pulse spot welding (MPSW) is a safe, efficient and environmentally friendly process, which is very suitable for joining aluminium alloys. AA5052 aluminium alloy sheets were joined by MPSW. Specifically, the bump on the flyer plate was driven to impact the parent plate at high velocity to achieve metallurgical bonding. The formation process, mechanical properties and micro-morphology of the joint were studied. The results showed that the bump of the flyer plate impacted the parent plate at high velocity caused by Lorentz force to form welding seam. The shape of the welding seam was two incompletely continuous symmetrical elliptical arcs due to the different welding velocities and welding angles in each zone. The strength of the joint was higher than that of the base metal at appropriate process parameters. Specifically, the relatively better process parameters were welding gap of 1.4 mm, welding diameter of 16 mm and discharge energy of 36 kJ. The maximum loads of tensile shear and cross-tension were 4887 N, 1744 N. There were a large amount of dimples at the fracture of welding seam, and the toughness of joint was good.