Experiment and Simulation of Metal Jet in Magnetic Pulse Welding of Al-Cu Sheet

In recent years, magnetic pulse welding (MPW) technology has shown broad application prospects because of its unique advantages in dissimilar metal welding. The metal jet can clean up the dirt and oxide layer on the surface of the workpiece and promote metallurgical bonding, which is the key step in the MPW process. To explore the formation mechanism and characteristics of the metal jet, an experiment platform and integrated observation system for MPW was established in this work to carry out welding experiments on Al and Cu sheets. The complete metal jet trajectory was captured, and a smoothed particle hydrodynamics (SPH) simulation model was established based on the calculation of collision speed and collision angle. The results show that when the discharge voltage is 15 kV, the collision speed is about 404 m/s and the collision angle is about 17º. The metal jet is generated at the angle between the Cu and Al sheets, forming the bright flash. And the intensity of the flash caused by the metal jet first increases and then decreases. The metal jet is composed of metal particles that fall off the surface of the sheet after the collision, with the characteristics of high temperature and high speed. This work can provide theoretical support for the in-depth study of the MPW mechanism and improvement of the welding effect.