光纤激光焊接机身壁板T型结构焊缝成形控制

Shaping Control of Welds for Fiber Laser Welding T-Section of Fuselage Panels

采用双侧光纤激光同步焊接2060／2099铝锂合金机身壁板T型结构（蒙皮和桁条），对成形控制和横向（LT）拉伸性能进行研究及简要分析。研究结果表明：光束入射角度在可调范围内尽量小，以实现蒙皮与桁条形成良好的熔合；当光束入射位置偏移桁条0．1mm时，焊缝轮廓角度在45°～50°之间，T型接头横向拉伸强度达到最大；严格控制光束间距实现双侧熔池相互贯通以保证双侧焊缝组织的均匀性和提高接头力学性能；匹配送丝速度和焊接速度合理的比值，以实现焊缝表面平滑过渡。对于焊缝熔合充分且组织均匀的焊接接头，焊缝熔深是制约横向拉伸强度的关键因素，熔深控制在1mm以内，接头横向拉伸强度平均为蒙皮母材强度的80．1％，最大可达蒙皮母材强度的82．1％。

Double-sided fiber laser beam welding is used to synchronously weld T-section of fuselage panels （skins and stringers） for aluminum-lithium alloy 2060/2099 and shaping control is analyzed as well as long transverse （LT） tensile performance. The results indicate that a good fusion between skins and stringers can be obtained by using incident beam angle as small as possible in an adjustable range. The LT tensile strength reaches the maximum when the incident beam position is 0. 1 mm on the stringer yielding a 45°- 50° weld beam angle. To ensure weld microstructure uniformity and improve the T-joints＇ mechanical properties, beam separation distance must be strictly controlled to achieve the fusion of the double-sided welds in a common molten. In order to realize smooth transition of the weld Surface, the ratio of wire feeding speed to welding speed should be matched with a reasonable value. For welds with a fully fusion and uniform microstructure, the key factor restricting the LT tensile strength is weld penetration. The average LT tensile strength reaches 80.1% of that of the base materials and the maximum rises up to 82, 1%, when weld penetration is controlled in 1 mm.