2060铝锂合金光纤激光焦点旋转填丝焊工艺研究  

Fiber Laser Filler Wire Welding of 2060 Aluminum-Lithium Alloy with Laser Focus Rotation

作　　者：武强[1] 姜仁杰 李新桐 邹江林[1] 肖荣诗[1] Wu Qiang;Jiang Renjie;Li Xingtong;Zou Jiangling;Xiao Rongshi(Intelligent Photonic Manufacturing Center,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing100124 China)

机构地区：[1]北京工业大学材料与制造学部智能光子制造研究中心,北京100124

出　　处：《中国激光》2021年第22期116-125,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金面上项目(51775009)。

摘　　要：采用光纤激光焦点旋转的焊接方法进行2 mm厚2060铝锂合金薄板填丝(ER4047)焊接试验。利用高速摄像仪观察焊丝熔滴过渡行为及熔池流动行为,采用光学显微镜、能谱仪、X射线衍射仪、扫描电镜、显微硬度仪及拉伸试验机对焊缝成形质量、气孔形貌、显微组织、化学成分、断口形貌、硬度及接头强度进行分析。结果表明:旋转的激光焦点周期性地作用在熔池及焊丝末端,致使熔池长度增加,熔池流动更平稳且波动幅度减小;焦点旋转可以有效改善焊缝成形,抑制飞溅和气孔的产生;焊缝等轴细晶区的宽度及该区的晶粒尺寸减小,靠近细晶区的柱状晶尺寸也有所减小。与非激光焦点旋转焊接接头相比,激光焦点旋转焊接接头熔合线附近的显微硬度和强度略有升高,接头断裂在熔合线附近,断口呈混合断裂特征。Objective 2060 aluminum-lithium alloy is a third-generation aluminum-lithium alloy,which has excellent performance,such as low density and high specific stiffness.It has broad application prospects in the aerospace field.Fiber laser welding technology is rapidly developing because of high welding speed and high efficiency.The lightweight material of the aluminum-lithium alloy,combined with fiber laser welding,can satisfy the lightweight requirements of aircraft.Because of the large thermal expansion coefficient of the aluminum-lithium alloy and easy burning of elements,the problems of cracks,pores,and mechanical properties are concerning.Although the crackassisted process can effectively suppress cracks,the pores and mechanical properties still need to be improved.Moreover,the filler wire welding process causes problems such as high light wire matching and complicated melting and solidification behavior of the wire.In this study,focus rotation and filler wire were adopted in the fiber laser welding(denoted as laser welding-FRFW)of 2 mm-thick 2060 aluminum-lithium alloy to analyze the impact of laser focus rotation on the weld formation,porosity,distribution of microstructures in the weld,and the mechanical properties of the welded joint.Methods The test specimen was a piece of 2060-T8 aluminum-lithium alloy.We used 4047 welding wires with a diameter of 1.2 mm.The YLS-6000 fiber laser was used.The core diameter of the transmission fiber was 200μm,the focal length of the collimating lens was 200 mm,and the focal length of the focus lens was 300 mm.The wedge angle of the wedge prism was designed to obtain the required laser focus rotation radius.A laser focus rotating devicewas used to regulate the rotational speed of the wedge prism.We adopted the process parameters as follows:laser power,3.8 k W;welding speed,3 m/min;wire-feeding angle,45°;wire-feeding speed,3 m/min;laser-wire distance,0 mm.Furthermore,a color high-speed camera was used to observe the droplet transfer behavior in the welding process.When the wel

关 键 词：激光技术 铝锂合金 填丝焊接 光纤激光 焦点旋转 组织 力学性能 

分 类 号：TG442[金属学及工艺—焊接]