电弧状态对铝合金激光-电弧复合焊接工艺过程稳定性的影响

Effect of Arc on Process Stability of Laser-Arc Hybrid Welding of Aluminum Alloy

焊接过程稳定性是决定焊缝质量的重要因素,而焊接飞溅和焊缝表面形貌是焊接过程稳定性的直接体现。为了得到稳定的铝合金激光-MIG电弧复合焊接过程,本研究采用高速摄影的方法统计焊接飞溅数量,并分析焊缝表面成形质量,对焊接过程稳定性进行了综合定性评价,结合激光焊接与电弧焊接基本原理,探讨了减少飞溅、稳定焊接过程的原理。在本试验条件下,提高纯Ar保护气的流量、电弧弧长和光丝间距,降低电弧电磁收缩力,可以减少飞溅数量。复合焊接飞溅数量减少的主要原因可以归结为两点:激光对熔池的预热作用扩大了熔池前端的面积,使熔滴融入熔池的过程更平稳;工艺优化使电弧对熔滴的作用力保持在合理范围。相关结果为复合焊接稳定的工业应用奠定了工艺基础,指明了工艺优化方向。

The stability of the welding process is an important factor determining the quality of the weld seam,and the welding spatter and weld surface morphology are direct manifestations of the stability of the welding process.In order to obtain a stable aluminum alloy laser-arc hybrid welding(LAHW)process,this study used high-speed photography to count the number of welding spatters and analyze the weld surface forming quality.A comprehensive qualitative evaluation of the stability of the welding process was carried out.Combined with the fundamental principles of laser welding and arc welding,the mechanism of reducing spatter and stabilizing the welding process is discussed.Under the present experiment condition,the welding spatter could be reduced by appropriately increasing the Ar shielding gas flow,arc length,distance between the center of laser beam and wire tip or decreasing the electromagnetic contraction force of the arc.The LAHW spatter suppression mechanisms are that:Firstly,the preheat effect of laser enlarges front welding pool which stabilizes metal transfer;Secondly,the optimized processing keeps reasonable force of arc on molten drop.The stable LAHW process contributes to the success of industrial application.