铜及其合金材料热导性良好、反射率高, 采用单一激光焊接难度较大。提出绿-红外双波长脉冲激光同轴复合焊接方法, 并研制了焊接系统。系统的绿激光脉冲能量为255.4 mJ, 功率稳定度为±2%; 消色差焊接头保证了T2紫铜的双波长激光同轴复合精密焊接。对焊缝进行显微组织及显微硬度测试, 结果表明, 焊缝光滑平整, 无缺陷; 焊缝正面高度与母材区的持平, 宽度约为0.5 mm, 焊缝反面高度略低于母材区, 宽度约为0.4 mm; 焊缝平均显微硬度为134 HV, 为母材的64.8%, 未出现严重的软化现象。

Due to the good thermal conductivity and high reflectivity, copper and its alloys are difficult to be welded by the single laser. The method of green-infrared dual-wavelength pulsed laser coaxial hybrid welding is proposed, and the welding system is developed. In this system, the pulsed green laser is with the energy of 255.4 mJ and the power stability of ±2%. The achromatic welding head ensures the coaxial hybrid precision welding of T2 red copper by a dual-wavelength laser. The microstructure and microhardness of welds are tested. The results show that the welds are smooth with no defects. The weld height of topside equals that of the base metal zone. The weld height of backside is slightly lower than that of the base metal zone. The weld widths of topside and backside are 0.5 mm and 0.4 mm, respectively. The average microhardness of welds is 134 HV, and 64.8% of that of the base metal zone. No serious softening problems occur.