Numerical simulation and experimental study on electromagnetic punching-flanging process of 6061 aluminum alloy sheets

In order to shorten flanging process and improve manufacturing efficiency, an electromagnetic punching-flanging (EMPF) process was proposed in this work. The EMPF experiments were performed with 6061 aluminum alloy sheets and an electromagnetic-mechanical-fracture numerical simulation was established. The flange formation mechanism and relationships between die-fitting gaps/flange heights and discharge energies were analyzed. The thickness reductions of flanged parts were measured to characterize the flange forming quality. Results showed that sheet deformations during EMPF process mainly occurred in the flanging stage of sheets, and the relationship between flange heights and discharge energies could be represented by a quadratic function. The appropriate increase of discharge energies could reduce the die-fitting gaps. The die-fitting gap (0.506 mm) was minimum under the discharge energy of 7 kJ, which was an optimum discharge energy in this work. The thickness reduction gradually slowed down from this position to fillet positon. The maximum and average thickness reduction rates relative to sheet thickness were 13.6 % and 8.2 % for optimum discharge energy, respectively. Numerical simulation and experimental investigations illustrated that the electromagnetic punching-flanging process can be used for manufacturing flanged parts with high quality.