基于LabVIEW的激光-MIG复合焊接过程等离子体监测  

Plasma Monitoring During Laser-MIG Hybrid Welding Process Based on LabVIEW

作　　者：马尧睿 蔡创 刘致杰 谢佳 杨策 Ma Yaorui;Cai Chuang;Liu Zhijie;Xie Jia;Yang Ce(Institute of Materials Science and Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031

出　　处：《中国激光》2022年第2期147-158,共12页Chinese Journal of Lasers

基　　金：国家自然科学基金(51805456);中央高校基本科研业务费专项资金(2682021CX108);四川省科技计划项目(2021YFG0209)。

摘　　要：在LabVIEW环境下设计了一套焊接过程监测系统,该系统可以采集激光-MIG复合焊接等离子体的光学信号以及焊接电流、电压这两种电信号,并以TDMS格式输出。焊接前使用最大类间方差法对焊丝与工件的图像进行二值化处理,然后对二值化图像使用形态学滤波器进行降噪滤波并细化,接着采用一种基于路径追踪的分叉去除算法去除细化结果中的分叉,最后使用HUBER线性拟合法确定激光束的入射位置。对焊接时的等离子体高速摄像照片进行图像处理,获得了激光在等离子体中的传输距离(DLTP)。将DLTP的计算值与实测值进行对比,可知所设计系统的计算准确度为96.5%。Objective With the development of high-speed rail lightweight, aluminum alloys as a low density and highperformance material are widely used in the body and important parts of the train. Compared to traditional welding methods, laser-MIG hybrid welding has the advantages of high welding efficiency and joint strength, strong gap adaptability, small residual stress, and deformation, while welding aluminum alloys. A fast-changing unsteady state can be observed during the laser-MIG hybrid welding process of aluminum alloys. The refraction and absorption of the incident laser by the laser-induced plasma occur during the welding process. The laser-induced plasma in the welding process fluctuates very violently leading to the fluctuation of laser energy input and defects of the weld quality. Therefore, the monitoring of plasma signals during the laser-MIG hybrid welding process of aluminum alloys has critical guiding effects in optimizing welding process parameters, reducing welding defects, and developing hybrid welding technology.Methods A 10 k Wdisk laser(TRUMPF Tru Dsk-10002 i disk laser) with a wavelength of 1030 nm and a welding machine(Fronius Trans Plsu Synergic 4000) with a welding current frequency of 125 Hz were used. The high-speed images of welding plasma were captured via a high-speed camera(Photron FASTCAM SA4 model 500 K M2) equipped with several ND4, ND8 attenuators, and an 808 nm filter. The thickness of the aluminum alloy samples is 8 mm. Meanwhile, the ER5356 weld filler wire was used. To improve the test efficiency, the bead-on-plate welding method was used(Fig. 12). The argon with a purity of 99.99% was used as the shielding gas. During the welding process, the laser was transmitted through the optical fiber to the laser head fixed on the ABB IRB 6640 M2004 six-joint robot, which formed a hybrid heat source combined with the welding torch. The high-speed camera was facing the work zone, and the hybrid plasma was observed with the illumination of the auxiliary light source. The plasma was located at

关 键 词：激光技术 激光-MIG复合焊接 监测系统 等离子体高速摄像照片 形态学滤波器 图像处理 激光在等离子中的传输距离 

分 类 号：TG403[金属学及工艺—焊接]