利用高速摄像仪自带的多重成像镜头观测了CO₂激光-钨极稀有气体(TIG)电弧复合焊接等离子体的多重成像特征。结果表明:采用多重成像技术可同时获得同一个等离子体的三个面积逐渐减小、光强逐渐增大的区域形态;氩气保护复合焊接等离子体的颜色由蓝白色逐渐变为红色,不能区分金属和氩弧等离子体;在氦气保护下,自第二次成像开始,氦弧等离子体几乎不可见,仅余仍为亮白色的金属等离子体;等离子体中的氦在可见光区辐射的线状谱较少(光强相对弱),是氦气保护下能明显区分出金属等离子体的主要原因;复合焊接中金属等离子体与保护气等离子体没有充分混合,电弧等离子体对金属等离子体的形态具有显著影响。

The multi-imaging characteristics of CO2 laser-tungsten inert gas (TIG) arc hybrid welding plasma are observed by a high-speed camera with a self-made multi-imaging system. The research results show that three regions of the same plasma with decreasing area and increasing light intensity can be obtained at the same time by multiple imaging technology. The color of plasma gradually changes from blue and white to red in argon shielded hybrid welding, and the metal vapor plasma and argon arc plasma can't be distinguished. Since the second imaging, helium arc plasma is almost invisible, and the remaining metal plasma is still bright white. The less linear spectrum of helium radiation in the visible region (relatively weak light intensity) is the main reason why metal plasma can be distinguished clearly in helium protection; the metal plasma and shielding gas plasma are not fully mixed in hybrid welding. And the morphology of the metal plasma can be obvious influenced by the arc plasma.