铝锂合金交流CMT焊接高频脉冲复合电弧焊接技术研究进展

Alternating current CMT and high frequency pulse composite arc on Al-Li alloys welding technique

随着兵器工业和航空航天领域对高强、轻质Al-Li系合金结构件的迫切需求,实现Al-Li合金的可靠高效连接显得日益重要。针对在焊接Al-Li合金使用传统焊接方法易出现热输入量大、焊接稳定性差导致的组织性能差及气孔、热裂纹缺陷等问题,提出采用交流CMT焊接与DC-DC变换高频脉冲复合电弧焊接技术进行Al-Li系合金焊接,利用低热输入量的交流CMT焊接电弧破除合金表面氧化膜,减小熔池气孔和热裂纹敏感性,利用高频脉冲电弧的高频效应及其电弧超声细化晶粒,提高接头强度,获得良好的结合性能。

With the urgent needs of high strength,lightweight Al-Li alloy structure in weapons industry and aerospace areas,reliable and efficient connection of Al-Li alloy appears increasingly important.It is prone to porosity,thermal cracks and other defects in traditional Al-Li alloy welding methods because of oversized heat input and poor welding stability.In response to these issues,this paper proposed a novel technique using alternating current CMT and DC-DC high-frequency pulsed composite arc on Al-Li alloy welding.In order to get good bonding properties,the low heat input of alternating current CMT arc is used to break oxidation film in alloy surface,reduce porosity and the thermal crack sensitivity of weld pool.The high frequency effect of high frequency pulse arc and its arc ultrasonic is used to refine grains and improve joint strength.