Distribution of Electromagnetic Field and Pressure of Single-Turn Circular Coil for Magnetic Pulse Welding Using FEM

Abstract

Magnetic pulse welding (MPW), which is uniquely advantageous in welding electrically conductive similar and dissimilar pipe fittings, is a contactless welding technology based on high-speed magnetic impulse shaping and solid-phase diffusion welding. This has proven to be an effective solution to specific manufacturing problems, especially for leak-proof dissimilar pipe joints required to sustain high pressure, which is very difficult to achieve by conventional techniques. For achieving the successful weldament, it is essential to understand the effect of various process parameters to generate proper weldability window. In the present work, the distribution of electromagnetic force and magnetic field of single-turn circular coil for MPW has been investigated using FE simulation. A three-dimensional (3D) electromagnetic FE model has been developed using commercially available ANSYS-EMAG application software. A single-turn inductor coil of Cu material is chosen for the analysis. Compression joining of tubular metallic assembly with flyer tube as Al6061 and target tube as SS304 is simulated in ANSYS Maxwell 3D to study the influence of varying process parameters like air gap between the tubes, tube thickness, and gap between the flyer tube and the coil with respect to the input voltage. FE simulation results for weld formation are verified with the analytical results and the data available in the literature. The study reveals that for effective welding, estimation of electromagnetic field and electromagnetic force has a significant role which is governed by the process parameters of applied voltage and air gap. The presented information can assist to understand process physics, coil reliability, and prediction of mechanical behavior of the workpiece.