铝合金三丝双脉冲MIG焊熔滴过渡及电信号分析

Analysis of droplet transfer and electrical signal in triple-wire double-pulse MIG welding of aluminum alloy

文中搭建了三丝双脉冲MIG焊系统,采用高速摄像电信号同步采集系统对焊接过程进行实时监测,研究了铝合金三丝双脉冲MIG焊熔滴过渡行为以及双脉冲频率对焊缝成形的影响.结果表明,弱脉冲向强脉冲过渡时,熔滴过渡表现为一脉一滴;强脉冲向弱脉冲过渡时,在开始阶段,焊丝发生再引燃,在结束阶段,熔滴过渡表现为两脉一滴;双脉冲频率增加,焊缝鱼鳞纹变密,双脉冲频率为3 Hz时,鱼鳞纹疏密均匀,焊缝成形最佳.

Triple-wire double-pulse MIG welding system has been built up in this test.The welding process was monitored by the high-speed photography and electrical signal collection system.The droplet transfer modes of triple-wire double-pulse MIG welding of aluminum alloy and the influence of double-pulse frequency on weld bead formation were studied.The results of experiment show when weak pulse transferred to strong pulse,the droplet transfer mode was one drop per pulse.When strong pulse transferred to weak pulse,the re-ignition of wire occurred during the beginning of transition and the droplet transfer mode was one drop two pulses during the end of transition.With the increase of the double-pulse frequency,fish-scale pattern of weld bead was more and more dense.When the double-pulse frequency was 3 Hz,the density of fish-scale pattern was uniform and weld bead formation was the best.