Design and Optimization of Pulse Forming Networks for Electromagnetic Manufacturing Systems

Electromagnetic manufacturing systems utilize an intense transient electromagnetic current pulse generated from the discharge of a pulsed power source into the tooling coil (actuator coil). The most widely used pulsed power source is a series of capacitor banks. The magnetic field produced by the pulsed current induces a large current in the workpiece to generate very high electromagnetic pressure, which is then used to achieve the required objectives. The intensity of the electromagnetic pressure on the workpiece is entirely determined by the characteristics of the pulsed power system. This system, however, has very low efficiency due to poor magnetic coupling between the tooling coil and the workpiece.The induced current in the workpiece is a strong function of the current waveform in the tooling coil (actuator coil). The quality of deformation of the workpiece depends on the magnitude and spatial distribution of the electromagnetic pressure. Therefore, we need to optimize the pulse parameters to maximize the efficiency of the manufacturing process. It requires identifying important pulse parameters such as rise time, fall time, magnitude of the current etc., and relevant control variables to achieve the required deformation during the manufacturing process.In this paper we have analyzed the forming characteristics of the workpiece with respect to the temporal variation in the magnetic pressure being applied on the workpiece. The studies are performed for a free forming experiment using a uniform pressure tooling coil.