激光-双MIG电弧复合焊耦合机制及熔滴过渡研究  

Study on Coupling Mechanism and Metal Transfer in Laser Double-Wire MIG Arc Hybrid Welding

作　　者：胡连海[1] 黄坚[2] 吴毅雄[2] 许昌玲[1] 

机构地区：[1]石家庄铁道大学材料科学与工程学院河北省交通工程材料重点实验室,河北石家庄050043 [2]上海交通大学上海市激光制造与材料改性重点实验室,上海200240

出　　处：《中国激光》2016年第6期87-94,共8页Chinese Journal of Lasers

基　　金：河北省自然科学基金(E2013210030);河北省高等学校科学技术研究指导项目(Z2012010)

摘　　要：激光-双MIG(熔化极稀有气体保护)电弧复合焊具有熔深大、熔敷效率高、焊接质量好等特点,然而由于其耦合机理复杂,给应用带来了一定的困难。基于电磁场理论提出了激光与双电弧耦合机制,当激光光致等离子体中间部位的电子受到两个电弧产生的洛伦兹力和电场力相差较大时,等离子体两端的电子分布会不均匀,这使得一端电弧发生弯曲,沿焊丝轴向的促进力减小,熔滴过渡困难。当激光光致等离子体中间部位的电子受到两个电弧产生的洛伦兹力和电场力大致平衡时,电子能够比较均匀地分布在等离子体的两端,吸引稳定电弧,利于熔滴过渡。采用高速摄影系统和电信号采集系统研究激光-双MIG电弧复合焊接过程,结果表明:当工艺参数不合适时,电弧发生弯曲,导致不稳定的大颗粒过渡和短路过渡;当工艺参数合适时,两个电弧根部被固定在激光光致等离子体的下部,形成稳定的射流过渡。Laser double-wire MIG arc hybrid welding has the characteristics of large weld penetration, high metal deposition rate and good welding quality, however, the underlying interaction is so complicated that it brings some difficulties in the practical applications. A coupling mechanism between two arcs and laser-induced plasma is proposed based on the electromagnetic field theory. When the difference between the Lorentz force and electric field force generated by the two arcs acting on the electrons in the middle part of the laser-induced plasma is significant, the electron distributions at two ends of plasma are not uniform, which causes one arc bend, the driving force to be reduced along the wire axis, and the droplet transfer become more difficult. When the two force are balanced, the electron distributions at two ends are relatively uniform, and the plasma can attract and stabilize the two arcs, which results in a smooth droplet transfer. Laser double-wire MIG arc hybrid welding process is experimentally studied by using the high speed photography system and signal acquisition system, and the results show that when the welding process parameters are not suitable, the arc severely deviates from the wire axis so that unstable globular transfer and short circuiting transfer occur. In contrast, when the welding process parameters are suitable, the roots of the two arcs are fixed to the bottom of laser-induced plasma and a smooth and directional spray metal transfer with low spatter loss is achieved.

关 键 词：激光技术 激光-双熔化极稀有气体保护电弧复合焊 耦合机制 激光光致等离子体 电弧 熔滴过渡 

分 类 号：TG456.7[金属学及工艺—焊接]