Comparison of electromagnetic-driven stamping and electromagnetic forming limit curves for AA5182-O aluminum alloy sheet

The strain paths of electromagnetic forming limit curve are usually limited due to the restricted design of coil, die, or workpiece. The electromagnetic-driven stamping was suggested to obtain the high-speed forming limit curve of AA5182-O aluminum alloy sheet. The hemispherical punch was pushed by the drive plate with the Lorentz forces to impact on the workpiece. The cross-sectional method was used to determine the experimental limit strains of workpieces. The electromagnetic and mechanical fields were sequentially coupled for numerical simulation of the electromagnetic-driven stamping experiment, and the equivalent plastic strain increment ratios of the necking and safe zones were calculated to determine the simulated limit strains. A series of linear strain paths were attained to contain the uniaxial tension to biaxial tension states. The experimental and simulated forming limit curves showed good agreement to validate the electromagnetic-driven stamping experiment. The electromagnetic-driven forming limit curve was compared with the quasi-static and electromagnetic forming limit curves. Although the electromagnetic-driven forming limit curve is lower than the electromagnetic one, it is higher than the quasi-static one.