An innovative coil for magnetic pulse welding of dissimilar sheet metals: Numerical simulation and experiments

Abstract

Magnetic pulse welding (MPW), as an environmentally friendly room temperature solid-state welding technology, usually involves low energy utilization efficiency, resulting in the need for higher energy to achieve metallurgical welding. This study proposed an innovative coil structure for increasing energy utilization efficiency during MPW. The current signal and structural strength of new coils with different turns were analyzed by numerical simulation. The results show that, different from traditional E-shaped and H-shaped single turn coils, the new structure can achieve nearly n-time amplification of current, which enabling the flyer plate to achieve the critical speed of metallurgical welding at lower energy. The 7-turn coil has higher structural strength and pulse current compared to the other coils in this study. The initial current was amplified 5.2 times by the 7-turn coil and welding of Al-Fe plates was achieved. The microstructures at the welding interface exhibit typical metallurgical features, including wave interfaces, element diffusion layers, and intermetallic compounds. The fracture location of the AA1060 (thickness δ: 0.5)-DP600 joint appeared on the base metal. The fracture morphology of AA5754 (thickness δ: 1.0)-DP600 joint shows that a large amount of aluminum element remains on the DP600 plate. Therefore, the new coil can increase the energy utilization rate during the welding process and achieve stable metallurgical welding of dissimilar materials.