线圈和模具结构对板材电磁脉冲成形效率的影响

Effects of the die radius and coil structures on electromagnetic pulsed forming

电磁成形是一种高速率成形方法,可大幅度提高材料的成形极限。但是成形过程中仅有一小部分电能被转变成工件的塑性变形能。为了提高材料塑性变形的能量利用率,本文采用实验和模拟手段分析了不同尺寸的凹模和线圈结构对铝合金板材电磁成形后的轮廓、塑性应变和能量利用率的影响规律。对比板材的最终变形轮廓,模拟与实验结果一致。同时发现当放电参数一定,线圈半径接近于凹模半径与圆角半径之和时,板材的塑性变形能最大,达到189.92J,能量利用率达到4.5%。

Electromagnetic forming is a kind of high-velocity forming technology based on the repulsive forces generated by opposite magnetic fields in adjacent conductors, which can significantly increase materials＇ forming limit. One disadvantage of the electromagnetic forming process is poor efficiency. This is because just a small part of energy is used for plastic deformation. In order to improve energy efficiency, this study analyzed the effect of different die dimensions and coil structures, through the comparison for profile, plastic deformation and energy efficiency after electromagnetic forming of aluminium alloy sheet. The validation of the simulation model is proved according to experiment value. When the die radius is approximately to the sum of coil radius and corner radius, the maximum values of plastic deformation energy and energy efficiency are obtained, respectively （Ea=189.92 ,η7）= 4.5%）.