采用波长为1070 nm的光纤激光, 对厚度均为0.2 mm的304不锈钢和T2紫铜超薄板进行了激光搭接焊。采用钢-铜-钢三层搭接方法时, 能得到良好的焊缝和较宽的工艺窗口。焊缝显微结构呈现出与焊缝边缘平行的黑色层状花纹。能谱分析结果表明, 焊缝下部的铜含量高于上部的。显微硬度测试结果表明, 接头硬度最低区域为铜层热影响区, 单侧热影响区的宽度在1 mm左右。拉伸试验结果显示, 断裂位置处于铜层热影响区, 其最大拉伸强度为213 MPa。

Laser lap welding of 0.2 mm-thickness 304 stainless steel and 0.2 mm-thickness T2 red copper ultra-thin sheets is conducted by using a fiber laser with a wavelength of 1070 nm. With the steel-copper-steel tri-layer lap welding method, good welds and wide process windows can be obtained. Black layered patterns parallel to the weld edge are observed in the weld microstructure. Energy spectral analysis results show that the content of copper at the weld bottom is higher than that at the weld top. The microhardness test results show that the lowest hardness zone is in the heat affected zone of the copper sheet, and the unilateral width of the heat affected zone is about 1 mm. The tensile test results show that the fracture occurs in the heat affected zone of the copper sheet, and the maximum tensile strength is 213 MPa.