激光焊接专用气动喷嘴的研究

Study on aerodynamic nozzle specialized for laser welding

针对高功率CO2 激光焊接 ,作者试验研究出一种气动喷嘴 ,用以保护导光聚焦系统 ,防止焊接过程中金属飞溅造成的镜片污染 ,通过对飞溅粒子运动轨迹的理论分析 ,设计出合理的喷嘴结构。采用气动喷嘴和普通同轴喷嘴 ,比较试验出高功率激光焊接过程中导光系统污染对激光功率的衰减、焊缝气孔率及有效熔深等的影响以及聚焦镜片上飞溅粒子的分布。结果表明 :气动喷嘴从本质上减少了聚焦镜上飞溅粒子的数量 ,使激光功率损失减少 ,有效焊接长度增加 ,并且横向气流没有对焊缝造成任何不利影响。

In this paper, an aerodynamic nozzle was investigated for protecting the beam deliveray system and preventing optics pollution from ejected particle vaporized on metallic surface during high power CO 2 laser welding. The suitable nozzle structure was designed on the basis of theoeretical analysis on moving trajectory of the ejected particle. The comparing experiments between aerodynamic nozzle and ordinary nozzle were performed to examine the influence of optics pollution on loss of laser power, porosity percentage of weld section; and efficient penetration depth, and also to inspect the distrubution of ejected particle on optics during laser welding. The studied results show that the aerodynamic nazzle substantially reduced the particle amount on the optics, so the loss of the laser power delivered to the workpiece was reduced, the effective weld lentgh was increased.The examination of the weld structure ensured that there was no interference with the quality of the weld due to the cross flow.