Experimental Validation of Analytical Model for Electromagnetic Forming Using a Uniform Pressure Actuator

For certain applications, the welding of dissimilar metals is highly desired, e.g. an automotive shaft assembly with both steel and Aluminum components, so that material properties can be tailored to specific locations within the assembly where required. Fusion welding cannot be used in such applications due to the disparity of the material properties involved and the concern of cracking due to intermetallic phases. Electromagnetic welding is a solid-state process where a capacitor bank is charged and then quickly dissipated into a magnetic coil. Eddy currents in the workpiece are created which repel the material from the coil at a high velocity, on the order of 200–300 m/sec. At a critical velocity, the impact energy welds the two components together. In this paper, an analytical model to predict workpiece velocities, which is attractive for its simplicity and cost, is presented and compared to experimental data. The model focuses on a Uniform Pressure Actuator [1], which accelerates sheet metal workpieces. In addition, magnetic effects of workpiece thickness are evaluated.