蓝光辅助红外MOPA光纤激光对纯铜薄片点焊的研究  

Blue Laser-Assisted Infrared MOPA Fiber Laser Spot Welding of Pure Copper Sheets

作　　者：王晨阳 林卿 吕超 王方伟 吕柳[2] 王锋 袁孝[3] Wang Chenyang;Lin Qin;LüChao;Wang Fangwei;LV Liu;Wang Feng;Yuan Xiao(Lingyun Photoelectronic System Co.,Ltd.,Wuhan 430205,Hubei,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China;School of Optoelectronic Science and Engineering,Soochow University,Suzhou 215006,Jiangsu,China)

机构地区：[1]武汉凌云光电科技有限责任公司,湖北武汉430205 [2]江苏大学机械工程学院,江苏镇江212013 [3]苏州大学光电信息科学与工程学院,江苏苏州215006

出　　处：《中国激光》2022年第16期67-75,共9页Chinese Journal of Lasers

基　　金：湖北省科技重大专项(2020AAA003)。

摘　　要：由于纯铜材料吸收的波长依赖性以及对红外激光吸收的温度依赖性和高导热性,1μm红外激光的纯铜焊接常常会出现焊接效果不稳定的问题,同时伴随着飞溅、孔洞等焊接质量问题。纯铜材料对激光的吸收具有很强的波长依赖性,在短波段的吸收显著增加,因此绿光和蓝光激光也被用来进行铜的焊接,并取得不错的焊接效果;然而,蓝、绿激光的高成本严重制约了其在精细微焊接中的应用。考虑到成本和焊接效果的平衡,本研究团队使用100 W/450 nm蓝色半导体连续激光辅助120 W/1.07μm MOPA红外光纤纳秒激光对纯铜薄片进行点焊实验,蓝光的主要作用是焊前预热和焊后保温。实验结果表明:与单纯的红外MOPA激光焊接相比,蓝光辅助红外MOPA激光焊接焊点的表面形貌、拉力、飞溅以及孔洞等都有明显改善。Objective Due to the dependence of absorption on wavelength and temperature as well as the high thermal conductivity of copper,the laser welding of copper with a 1μm infrared(IR)laser beam generally shows clear instability,splashes,and poor surface morphology.Thus,blue and green lasers were used to weld copper and excellent welding quality were obtained for the high absorption of copper in short wavelength.Currently,the cost of the red and green lasers is significantly high.Hence,considering the cost and welding quality,we employed an IR nanosecond MOPA fiber laser with a power and wavelength of 120 W and 1.07μm,respectively,to weld the copper sheets using a fiber-coupled blue diode laser with a power and wavelength of 100 W and 450 nm,respectively.The function of the blue laser is to preheat the surface of the copper sample to increase the effective absorption of the IR laser and slow the cooling process to help the expulsion of bubbles.As expected,surface morphology and tensile force of welded copper sheets are improved,and almost no splashes and microholes can be observed inside the pool in the welding area.Methods A dual-wavelength coaxial beam-welding system was designed.Two collimated beams from an IR MOPA fiber laser and a fiber-coupled blue diode laser were coaxially combined using a dichroic mirror,and further were focused on the workpiece using a galvanometer scanner and a dedispersive telecentric f-θlens.The weld position on the workpiece was controlled by scanner 2.Another galvanometer scanner,scanner 1,was inserted between the collimator of the IR MOPA beam and the dichroic mirror to control the movement of the MOPA beam inside the blue spot to achieve different welding modes,such as swing and spiral.In the experiments related to the tensile test,each workpiece sample was welded to four spots in a square-like pattern with a 2 mm pitch.The diameter of each welding spot is about 350μm.Copper sheets with a thickness of 100 and 200μm were welded onto a copper sheet with a thickness of 250μm,which w

关 键 词：激光技术 纯铜片 激光点焊 蓝激光 MOPA光纤激光 双波长 

分 类 号：TG456.7[金属学及工艺—焊接]