0.2mm厚GH4169薄片激光微焊接接头的组织性能

Microstructure and Properties of 0.2mm Thick Sheet GH4169 by Laser Microwelding

采用精密脉冲激光对厚度为0.2mm的GH4169高温合金进行焊接试验,利用光学显微镜、电子精密拉伸机等分析测试手段,研究了焊接工艺参数对焊缝形貌的影响,并对接头的金相组织与性能进行了测试、分析。结果表明,以氩气为保护气体,在功率12.8W,脉宽2.7ms,脉冲频率5.0Hz的工艺参数下,以激光为热源可成功实现0.2mm厚度GH4169的对接焊,焊缝成形良好、接头抗拉强度高于母材。焊接接头显微组织由焊缝中心区的细小等轴晶和熔合线附近的柱状晶组成,热影响存在晶间析出物导致腐蚀后有类似于裂纹的黑线生成。焊接接头的显微硬度高于母材。

The laser welding experiments on weld 0.2 mm thickness of the superalloys GH4169 with micro-laser pulse is carried out,the impact of welding process parameters on joints forming is analyzed,and the microstructure and properties of joints are studied by making use of optical microscopy,electronic precision stretching machine,and other analysis and detection methods.The results show that using argon as a shielding gas,0.2 mm thick GH4169 to the laser as heat source can be successful butt welding with process parameters of the power of 12.8 W,pulse width of 2.7 ms,pulse frequency of 5.0 Hz,and a good welded appearance is formed,and the joint tensile strength is higher than the base metal.The microstructure composed of welded joints is small equiaxed grains in the weld center and columnar grains near the fusion line,and in the heat-affected zone of the joints,there is a black line formation which is similar to the crack after corrosion because of the existence of grain boundary precipitates.Microhardness of welded joints is higher than that of the base metal.