高频脉冲耦合铝合金激光-MIG复合焊接熔滴过渡及其熔覆特性  

Droplet transfer in aluminum alloy laser-MIG hybrid welding coupled by high frequency pulses and its cladding characteristics

作　　者：朱宗涛[1] 王雪飞[1] 杨晓益 高健[1] 

机构地区：[1]西南交通大学材料科学与工程学院,成都610031

出　　处：《焊接学报》2016年第8期39-44,130-131,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51405398);中央高校基本科研业务费专项资金资助项目(2682015CX007)

摘　　要：采用高频脉冲电源与单脉冲MIG焊电源并联叠加的方式与激光热源复合,形成高频脉冲耦合激光-MIG复合焊接方法.在A7N01铝合金板材上进行堆焊试验,用高速摄像研究高频脉冲耦合后电弧及熔滴过渡行为的变化,并通过金相观察研究高频脉冲耦合对熔覆层成形及组织的影响.结果表明,高频脉冲耦合后弧长增大,电弧电压增大、基值电流减小,峰值电流变化不大;熔滴由部分亚射流过渡转变成完全射流过渡;熔覆金属表面光滑,"鱼鳞纹"特征消失,无"指状"熔深问题;熔覆层晶粒大小变化不明显,但晶粒内部强化相颗粒变小,分布更加均匀.High frequency pulses( HFPs) power source were parallelly connected with the power source of single-pulse mode MIG arc,which are applied to laser-MIG hybrid welding.The cladding on A7N01 aluminum alloy was executed to investigate the dynamics of droplet transfer and arc with the effects of coupled HFPs through high speed camera observation. The shaping-characteristic and microstructure of cladding layer were also studied by metallographic analysis. The results show that the arc length and voltage increase after HFPs being coupled. The base current of single pulse MIG arc decreases,while the peak current has little changes compared with that without HFPs coupling. In conventional laser-MIG hybrid welding,the droplets are partly transferred as meso-spray mode. The finger-penetration weld can be obtained,which probably causing defects in the weld root.After HFPs being coupled,partly meso-spray transfer changes to completely spray transfer. The surface of cladding layer becomes smoother with the disappearance of fish-scale pattern and fingerpenetration depth. Although the grain size has no significant changes,the size of second phase particles becomes smaller and more uniformly distributed in grains as strengthened phase.

关 键 词：铝合金 激光-MIG复合焊 高频脉冲 熔滴过渡 电弧超声 

分 类 号：TG456.9[金属学及工艺—焊接]