中文摘要：

针对为了实现铝-钢高效高质量的连接,提出一种高效低热输入的脉冲旁路耦合电弧熔化极惰性气体保护焊（Double-electrode gas metal arc welding,DE-GMAW）方法。为了使其焊接过程熔滴平稳过渡,分析旁路电弧对熔滴过渡时电流密度的影响,确定脉冲DE-GMAW熔滴过渡时电磁力的作用机制,在主路为脉冲电流情况下,分别设计旁路波形与主路组合形式即为恒定电流、交替脉冲电流和同步脉冲电流三种形式的研究,并使用高速摄像拍摄熔滴过渡图像,进行对比分析试验验证。结果表明,焊接电流波形及组合形式不同会导致作用于焊接熔滴的受力发生改变,从而使得焊接过程的稳定性与焊接质量也发生变化,对比分析得出采用同步脉冲电流时的脉冲旁路耦合电弧熔化极惰性气体保护焊焊接过程稳定、熔滴过渡均匀一致且焊缝成形平整美观。

英文摘要：

A method for high efficiency and low heat input, pulsed double-electrode gas metal arc welding（DE-GMAW）, joining of aluminium to steel is presented. In order to achieve the droplet steadily transfer at the process of welding, analyzing the bypass arc influence factors of the current density. The electromagnetic force action mechanism of the Pulsed DE-GMAW droplet transfer is established. Under the circumstance of the base metal is pulse current, studying on designing three forms of the bypass waveform and the base metal matching forms for constant current, alternate pulse current and synchronous pulse current, respectively. Use a high speed camera to capture the droplet transfer image for experiment comparison and verification. The results show that the different welding current waveform and the matching form would lead to the change of the forces exerted on the welding droplet, thus the welding process stability and weld quality is found changing. The pulsed DE-GMAW welding process is stability, the droplet transfer is uniform and the weld shape is smooth and beautiful by using of synchronous pulse current.