Electromagnetic Sheet Forming by Uniform Pressure Using Flat Spiral Coil

Abstract

The coil is the most important component in electromagnetic forming. Two important questions in electromagnetic forming are how to obtain the desired magnetic force distribution on the sheet and increase the service life of the coil. A uniform pressure coil is widely used in sheet embossing, bulging, and welding. However, the coil is easy to break, and the manufacturing process is complex. In this paper, a new uniform-pressure coil with a planar structure was designed. A three-dimensional (3D) finite element model was established to analyze the effect of the main process parameters on magnetic force distribution. By comparing the experimental results, it was found that the simulation results have a higher analysis precision. Based on the simulation results, the resistivity of the die, spacing between the left and right parts of the coil, relative position between coil and sheet, and sheet width significantly affect the distribution of magnetic force. Compared with the structure and magnetic force on a traditional uniform pressure coil, the planar uniform pressure coil can produce a uniform magnetic force distribution on the sheet, reduce the manufacturing difficulty, reduce manufacturing cost, and enhance the service life for the coil.

Springback Reduction of L-Shaped Part Using Magnetic Pulse Forming

“…For example, Cui et al [22] showed that the tube had a temperature rise of about 5 • C after discharge based on a numerical simulation. Cui et al [23] showed that the temperature on the sheet before and after discharge was changed a very small amount (0.1 • C) by the experiment. Moreover, we did not find any heating of the sheet in this experiment.…”