采用均匀压力线圈的铝合金曲面零件电磁校形

Electromagnetic sizing for aluminium alloy curved surface part by uniform pressure coils

回弹是铝合金板料成形工艺中不可避免的问题之一,直接影响到铝合金零件的成形精度。根据铝合金曲面零件的形状特征,采用具有3D随形结构的均匀压力线圈进行电磁校形,运用全过程多物理场耦合数值模拟方法分析铝合金曲面零件的应力状态与分布均匀性的演变过程,以揭示采用均匀压力线圈的铝合金曲面零件电磁校形机理。研究结果表明:冲压成形曲面零件在厚度方向上应力分布不均匀,外层受拉应力、内层受压应力,卸载后零件回弹严重;采用均匀压力线圈对冲压预成形零件施加整体近均匀分布的脉冲磁压力,曲面零件应力分布更均匀,内、外层均受拉应力,卸载后零件回弹大大减小,零件成形精度大幅提高。

Springback is one of the inevitable problems in the forming process of aluminum alloy sheet,which directly affects the forming accuracy of aluminum alloy part.According to the shape characteristic of aluminum alloy curved surface part,its electromagnetic sizing was conducted by the uniform pressure coils with 3D conformal structure,and the evolution process of stress state and distribution uniformity for aluminum alloy curved surface part was analyzed by the whole process and multi-physics field coupling numerical simulation method to reveal the electromagnetic sizing mechanism of aluminum alloy curved surface part by uniform pressure coils.The results show that the stress distribution along the thickness direction of stamping curved surface part is not uniform with the outer layer under tensile stress and the inner layer under compressive stress,and the springback of part is serious after unloading.However,when the stamping pre-forming part is applied an over nearly uniform pulse magnetic pressure by the uniform pressure coils,the stress distribution of curved surface part is more uniform with the outer and inner layers under tensile stress.Thus,the springback of part is significantly decreased after unloading,and the forming accuracy of part is well improved.