Selection of design parameters of working coil for Al/Cu tubular Magnetic Pulse Welding

MPW produces a high Lorentz force for welding through the interaction of magnetic fields between the working coil and outer workpiece. Therefore, the design of the working coil is crucial in the MPW process. In particular, it is important to understand and estimate the distribution of Lorentz force on the outer tube and the stress on the working coil. These factors greatly impact the efficiency of energy delivery and the durability of the process. The purpose of this research was to analyze the effect of coil design parameters on the Lorentz force and stress. The ultimate objective was to optimize these design parameters specifically for welding tubular workpieces; for this, an electromagnetic-mechanical FE-model was developed. The design parameters considered in this study included the angle, radius, and protruding length. The Lorentz force and stress were calculated based on these parameters. Notably, the response surface method (RSM) and sequential quadratic programing (SQP) were utilized to develop a prediction model and optimize the design parameters, respectively. The findings revealed that the protruding length and angle are significant design parameters. Consequently, a working coil was manufactured using the optimized design parameters, leading to a successful Al/Cu joint. These results emphasize the indispensability of optimizing design parameters to achieve high-quality joints.