铝合金板料成形间距对逐点连续电磁成形过程的影响规律

The Influence of Forming Space on Multi-Point Continuous Electromagnetic Forming Process

摘要:

电磁成形具有高速成形和提高材料塑性成形性能的特点，非常适用于准静态下难加工轻质铝合金材料的成形。在电磁系统中加入集磁器可以实现对工件的局部加工，但当电磁集中在小区域内多次成形时，由于两个成形点的距离较小，存在局部变形相互影响的区域，从而影响板料成形的均匀性。为研究逐点连续电磁成形过程中局部变形之间的相互作用机理，采用数值模拟结合实验验证的方法，探究了金属板料小区域逐点连续电磁成形过程中的变形行为，揭示了成形间距对板料成形涉及的电磁力、应变和最终成形效果的影响规律。研究结果表明，在单次电磁成形时，板料受到的电磁力呈环状分布，成形点中心受到径向与切向压应变和轴向拉应变，成形点四周受到径向拉应变和轴向与切向的压应变。在多次成形时，随着两成形点间距减小，板料在第二次成形时受到变形区的影响，影响间距为14 mm，板料中心所受的径向压应变和轴向拉应变增大，板料电磁力逐渐增大。第二成形点中心的成形高度随着两成形点间距的增加逐渐增加，两个成形点衔接处的凹槽深度也越深，而两个成形点衔接处的径向拉应变随着成形间距的增加表现为先增大后减小的趋势。本研究为在铝合金板料多点电磁成形过程中两点变形间距对电磁力和成形效果的影响提供了理论依据。

Abstract:

Because electromagnetic forming can improve the performance of material plastic forming， the use of magnetic collector in the electromagnetic system can realize the local processing of the workpiece， when the concentration in a small area of multiple forming， the distance between the two forming points is small and there is a local deformation of the area， which affects the uniformity of sheet metal forming.To investigate the interaction mechanism between local deformations during the point-by-point continuous electromagnetic forming process， using numerical simulation and experimental verification methods to explore the deformation behavior of the metal sheet during a continuous point-by-point electromagnetic forming process in a small area， revealing the influence of forming spacing on the electromagnetic force， strain and final forming effect involved in sheet metal forming. The results show that during the single electromagnetic forming， the plate is subjected to a circular distribution of electromagnetic force. The center of the forming point is subject to radial and tangential compressive strain and axial tensile strain， and its surroundings are subject to radial tensile strain and axial and tangential compressive strain. During multiple forming， as the distance between the two points decreases， the plate is affected by the deformation zones during the second forming，the influence range is 14 mm. The radial compressive strain and axial tensile strain on the center of the plate increase， and the electromagnetic force of the plate gradually increases. The forming height of the center of the second forming point increases gradually with the increase of the spacing between the two forming points， and the depth of the groove at the interface of the two forming points becomes deeper. The radial tensile strain at the interface of the two forming points shows a trend of first increasing and then decreasing with the increase of the forming distance.