Abstract: Non-eddy current electromagnetic forming is a new type of electromagnetic forming process, which realized high-speed deformation of the workpieces by directly applying pulse current on the metal workpieces instead of induced eddy current. The speed reached 102 m/s and the strain rate was as high as 103 s-1, which did not have a complex coil structure and the electromagnetic force was more uniform. For the 5052-O aluminum alloy sheets based on the non-eddy current electromagnetic forming experiments and simulation, the parameters in the Cowper-Symonds and Johnson-Cook high strain rate constitutive model were determined by using the inverse identification method. The flow stress of 5052-O aluminum alloy sheets was predicted at the high strain rate. By comparing the simulated and experimental results, it is confirmed that the Johnson-Cook hardening model is more accurate in describing the hardening behavior of the 5052-O aluminum alloy sheets. Finally, a validation experiment was conducted based on the determined parameters, and the deformation height, thickness, and strain at the marked points of the specimens in the simulation were compared with those in the experiments. The experimental data and the simulation results corroborate with each other, confirming the reliability.

Key words: electromagnetic forming, constitutive model, inverse identification, aluminum alloy sheet, high strain-rate forming

摘要： 非涡流电磁成形是一种新型电磁成形工艺，通过在金属工件上直接施加脉冲电流来代替感应涡流，实现工件高速变形，其速度达到102 m/s，应变率高达103 s-1，该工艺没有复杂的线圈结构，电磁力也更为均匀。针对5052-O铝合金薄板进行了非涡流电磁成形试验及有限元模拟，采用逆向识别方法对Cowper-Symonds和Johnson-Cook高应变率本构模型中的参数进行确定，并预测了5052-O铝合金在高应变率下的流动应力。通过比较模拟与试验中试样标记点的变形高度、厚度及应变，证实了Johnson-Cook硬化模型在描述5052-O铝合金硬化行为时更为精确。最后，基于确定的参数进行了验证实验，实验数据与模拟结果相互印证，证实了模型的可靠性。

关键词: 电磁成形, 本构模型, 逆向识别, 铝合金板, 高应变率成形