A Novel Coil Structure for Metal Sheet Magnetic Pulse Welding

Abstract

Magnetic pulse welding (MPW) of metal sheets is an efficient and environment-friendly room temperature solid-state welding technology. However, the process involves significant energy dissipation. Limited by the current coil structure, high energy is required to achieve metallurgical welding of metal sheets. To address this issue, novel coil principle and structure has been proposed. The current is simultaneously concentrated into a section of conductor by a unique circuit design, achieving current summation and amplification, thereby enhancing energy efficiency. Numerical simulations were performed to explore the effects of coil parameters on current density, Lorentz force, and flyer sheet motion, revealing that the coil structure can amplify current by 1.5 to 5.3 times as coil turns increase from 2 to 7. The flyer sheet velocity exceeded the critical welding velocity. Experimental results show successful welding of 1060 (1.0 mm) / DP450 (1.0 mm) at 6.05 kJ and 5754 (1.0 mm) / DP600 (1.0 mm) at 9.8 kJ, with all interfaces displaying metallurgical characteristics. These findings confirm the excellent welding capability of the novel coil at low energy, which results from a significant current amplification effect. This reduces the stringent requirements for magnetic pulse discharge equipment, thereby facilitating the further industrial application of MPW technology.