铜-铝电磁脉冲焊接界面形成过程的原子扩散行为

Atomic diffusion behavior in the interface formation of copper-aluminum electromagnetic pulse welding

电磁脉冲焊接技术以高压脉冲放电驱使异种金属可靠连接而备受关注,但其界面结合机制尚不明确.该文搭建了铜-铝电磁脉冲焊接综合试验平台,捕获了焊接的动力学过程,得到碰撞点速度与碰撞角度的变化规律.在此基础上,构建了基于分子动力学模拟的电磁脉冲焊接典型界面(平直界面与涡旋界面)形成过程的对应模型,探究了焊接中的原子扩散行为,并根据模拟结果计算了典型结合界面的扩散层厚度,同时采用透射电子显微镜分析了结合界面的微观结构.研究结果表明,剧烈碰撞驱使界面材料塑性变形,界面材料塑性形变形成冶金结合和机械咬合是铜-铝电磁脉冲焊接界面的结合机制,且涡旋界面处的原子扩散厚度大于平直界面.该文可为深入理解电磁脉冲焊接机理和调控焊接效果提供科学依据.

Electromagnetic Pulse Welding(EMPW)technology is widely concerned because of the reliable connection of dissimilar metals driven by high-voltage discharge.However,the interface bonding mechanism is still unclear.A comprehensive comprehensive experimental platform for copper-aluminum EMPW is set up,the welding dynamic process is captured,and the collision velocity and angle are obtained.Based on these parameters,a molecular dynamics simulation model is constructed for the formation of typical interfaces(flat interface and vortex interface)in EMPW.The atomic diffusion behavior in the welding process is studied,and the thickness of the diffusion layer at the typical interface is calculated.The microstructure of the bonding interface is analyzed by the transmission electron microscopy.The research results show that the severe collision drives the plastic deformation of the interface material,which forms metallurgical bonding and mechanical engagement.This is the bonding mechanism of the copper aluminum EMPW interface.And the atomic diffusion thickness at the vortex interface is greater than that at the flat interface.This paper can provide a scientific basis for further understanding the mechanism of EMPW and regulating the welding effect.