Influence of discharge current frequency on electromagnetic pulse welding

The present study aimed to investigate the influence of discharge current frequency on the deformation of aluminum alloy plates, jet, and welding effects. A modular EMPW system was designed and developed to carry out the welding of the aluminum alloy plate and copper plate. The system consists of four 14 kJ pulse power modules (PPMs), and the working number of PPM is controlled by a field-programmable gate array (FPGA), which also changes the capacitance and structure of the system. The result showed the discharge current frequency could be changed to 23.1 kHz, 17.8 kHz, and 15.2 kHz. By increasing the discharge current frequency, the discharge current amplitude and the Lorentz force were improved, and the deformation velocity of the aluminum alloy plate became faster. When the discharge current frequency was 17.8 kHz, the jet lasted the longest, with the longest length of the metallurgical bonding zone, which reflected the best welding effect. So the welding effect and the energy utilization rate can be improved by changing the discharge current frequency when the discharge energy is held constant. This work can provide a basis and reference for the parameters selection of the EMPW process.