管件电磁胀形过程中的材料变形性能问题与电磁力加载方案

摘要

Electromagnetic tube expansion has been extensively studied for its obvious advantages in lightweight alloy processing.Due to the reduction of wall thickness and the non-uniform deformation in axial direction, the development of the existing electromagnetic tube expansion has been restricted.In this paper, the method of electromagnetic tube expansion with axial compression is proposed, with which both the radial and the axial electromagnetic force are applied to decrease the reduction of wall thickness.The simulation results show that the reduction of wall thickness is reduced from 15.05％ to 9.65％.Furthermore, the method of electromagnetic tube expansion with concave coil to weaken the electromagnetic force in the middle part is proposed to improve the tube forming performance.In the simulation, the maximum deformation is 36 mm, and it is obvious that the radial electromagnetic force produced by "concave" coil can effectively solve the problem of non-uniform tube deformation.The improvement of electromagnetism force loading can effectively solve problems in electromagnetic tube expansion and promote its industrial application.%管件电磁胀形因其在轻质合金加工领域具有明显优势而得到广泛研究.传统电磁胀形过程中, 存在管件壁厚减小、轴向变形非均匀等问题, 制约了这一技术的发展.提出采用径向电磁力与轴向电磁力双向加载的施力方式, 构建轴向压缩式管件电磁冲胀形方法解决壁厚减薄问题;仿真数据显示, 因为轴向压缩, 管件壁厚减薄量由最初的15.05％降低至9.65％.进一步地, 提出采用凹型线圈削弱管件中部电磁力以提高管件成形质量的方法;算例中, 采用凹型线圈时最大变形区域为36mm, "凹型"分布的径向电磁力可有效改善管件轴向变形非均匀问题.显然, 电磁力加载方案的改进能有效解决管件电磁胀形存在的问题, 推动电磁成形技术工业化应用进程.