采用微型脉冲激光对0.2 mm厚的薄片状GH145高温合金进行对接焊, 利用光学显微镜、能谱分析仪、电子精密拉伸机等分析测试方法, 研究了焊接工艺参数对焊缝成形及接头抗拉强度的影响, 并对接头的金相组织与力学性能进行了测试与分析。结果表明, 焊接接头获得最大抗拉强度的最优工艺参数是脉冲功率百分比为17、脉冲宽度为4.0 ms、脉冲频率为2 Hz, 此时焊缝成形良好, 接头的承载能力达到了母材的97%。在其它工艺参数固定不变时, 脉冲宽度增大, 焊缝熔深增大, 接头抗拉强度也随之增大; 脉冲功率百分比过小和过大, 都会使接头的抗拉强度降低; 焊接接头显微组织由焊缝中心区细小的等轴晶和熔合线附近的柱状晶组成。焊缝区的硬度值明显高于母材区。

Using micro pulse laser carry out butt welding on 0.2 mm thickness of the thin slice superalloys GH145, the influence of welding process parameters on weld shaping and tensile strengeth of joints are analyzed, and the microstructure and mechanical properties of joints are studied by making use of optical microscopy, energy dispersive spectrometer, electronic precision stretching machine, and other analysis and detection methods. The results show that the optimized processing parameters that can get the maximum tensile strength are: the percentage of pulse power is 17, pulse width is 4.0 ms, and pulse frequency is 2 Hz, at this time a good welded appearance is formed, and the stretching resistance of the welded joint can achieve 97% of base metal. When other parameters are fixed, the pulse width increases, the weld penetration increases, and the tensile strength of joints also increased; When the percentage of pulse power is too small and too big, both of which lead to the decrease of the tensile strength of joints. The microstructure of the welded joints is composed of fine equiaxed grains in the weld center and columnar grains near the fusion line. The hardness of the weld zone is significantly higher than the base metal.