铝合金激光-电弧双面焊接特性

Welding Characteristics of Laser-Arc Double-Sided Welding for Aluminum Alloy

对5A06铝合金激光-电弧双面焊接(LADSW)特性进行研究,通过光谱诊断、电弧电压测量和基于斯塔克展宽法的电弧电子密度估算,对激光作用下的电弧物理特性进行分析。结果表明,借助电弧的辅助加热作用,可以明显地改善铝合金激光焊缝表面成形,显著降低甚至消除铝合金激光焊气孔。通过调整激光和电弧能量的匹配,可实现对接头形貌的控制,其中对称"X"型接头内部缺陷较少,具有最佳的力学性能,抗拉强度可达到母材的90%以上。与常规的钨惰性气体(TIG)电弧相比,典型的LADSW电弧形态具有明显的收缩;LADSW电弧具有更多的金属原子,而Ar原子则减少;LADSW电压下降,且更加稳定;LADSW电弧电子密度明显增加。与相同条件下的常规激光焊相比,LADSW激光焊等离子体面积略有增加。

Welding characteristics of laser-arc double-sided welding（LADSW） for aluminum alloy are studied.Arc physical characteristics are investigated by spectroscopic diagnosis,arc voltage measurement and estimation of electron density by Stark broadening method.With the preheating of tungsten inert gas（TIG） arc,the results show that the weld appearance of laser welding in LADSW is improved,and porosity in weld can be drastically reduced and even eliminated.The shape of weld cross-section can be controlled.Due to the symmetrical weld cross-section and less weld defect inside,the joint of the symmetrical ＂X＂ cross-section has the best mechanical properties.The tensile strength is more than 90% of the base metal.Compared with conventional TIG arc,the typical arc shape of LADSW is compressed.There are more metal atoms and less Ar atoms in LADSW arc than those of conventional TIG arc,and the arc voltage is decreased and more stable.The electron density of LADSW is higher than that of conventional TIG arc.The plasma area of laser welding is increased in LADSW compared with conventional laser welding under the same condition.