Synthesis of Pulse Forming Systems for Electromagnetic Manufacturing Process

The magnetic pressure required in an electromagnetic manufacturing process is generated by the passage of pulsed current through a tooling coil. However, the pressures generated are normally much less than the tensile strength of the workpiece. Therefore, in certain applications the workpiece is made to impact the die to create large amount of working pressures. Therefore, the impact velocity of the workpiece is a critical parameter for the deformation process. In this paper, a novel method to control the impact velocity of the workpiece and systematically determine the pulsed power circuit parameters required to achieve the desired velocity before the impact has been discussed. A model force waveform on the workpiece is proposed which is used as a load curve to simulate the mechanical deformation in the workpiece. An analytical model of the tooling coil and workpiece is presented to calculate the force on the workpiece. Curve fitting methods along with unconstrained optimization techniques are used to find the optimized values of the model waveform. Finally, the results obtained using the analytical methods are compared against those obtained using Finite Element Methods techniques and are found to be in good agreement with each other. The validated model is useful to calculate the design parameters required for the synthesis of the pulsed power circuit.