不同波长激光对激光—MAG电弧复合焊接熔滴行为的影响

通过计算分析了金属对Nd：YAG激光和CO2激光的吸收率;以8.0mm厚高强钢板为试验材料,采用高速摄像系统观测熔滴过渡模式和等离子体形态的变化.建立脉冲MAG焊接熔滴力学模型,从熔滴受力角度分析了不同波长两种激光YAG激光和C02激光在激光—MAG焊接中对熔滴过渡形式和熔滴过渡频率的影响.结果表明,Nd：YAG激光和CO2激光输出特性存在差异,金属表面对YAG激光的吸收率约为CO2激光的3倍多;在焊接电流180A、焊接电压26V、光丝间距3mm的相同条件下,YAG激光—MAG电弧复合焊接熔滴过渡频率高于CO2激光—MAG电弧复合焊接的熔滴过渡频率,且熔滴过渡频率均随着激光功率的增加而降低,但是增加等量的激光功率,YAG激光—MAG电弧复合焊接熔滴过渡频率下降幅度更大;CO2激光—MAG电弧复合焊接过程中,熔滴的过渡形式由射滴过渡转变为颗粒过渡,在YAG激光—MAG电弧复合焊接过程中,熔滴过渡形式主要为射滴过渡.

Influence of Different Laser Wavelength on Droplet Behaviors in Laser-MAG Arc Hybrid Welding

The absorptivity of metal to Nd：YAG laser and CO2 laser is analyzed through calculation.In this paper,8-mm- thick high strength is used as experimental material,a high speed eamera and a Hannover analyzer are used to observe droplet transfer mode and the morphological changes of plasma.From the angle of stress of droplet,this essay analyzes that influence of different laser wavelength on droplet transfer mode and droplet transfer frequency of laser-MAG（Metal active gas） arc hybrid wehting.The result indicates that output performance is different between Nd：YAG laser anti CO2 laser and the absorptivity of metal to YAG laser is about three times more than CO2 laser.Under the same welding parameters condition,droplet transfer frequency of YAG laser-MAG arc hybrid welding is higher than CO~_ laser-MAG arc hybrid welding,and both the droplet frequency decrease with the increasing of laser power,but the droplet transfer frequency of YA（7 laser-MAG are hybrid welding decreases nrore when both laser power increase to the same amount.In hybrid wehting process,droplet transfer mode of YAG laser-MAG are hybrid welding is the projected transfer.