为了提高紫铜对激光的吸收率，实现低功率激光的紫铜焊接，采用波长532 nm 的纳秒激光器对紫铜表面进行预处理，可使紫铜对1064 nm 波长激光的反射率从95%降低到15.5%，大大提高了焊接时激光的利用效率。同时，利用500 W 光纤激光器对厚度为0.3 mm 的紫铜激光焊接工艺展开了研究，对不同焊接速度和离焦量下的焊缝宽度、焊接强度、焊缝显微硬度进行了比较分析，找到了最佳的焊接参数。另外，对黑化处理与涂敷石墨后紫铜的焊接质量进行了比对，发现黑化处理后激光焊接的焊缝显微硬度和抗拉强度均优于涂敷石墨的情况。

To improve the copper absorption coefficient to lasers, a black-treating method is proposed. With this method, the reflection coefficient of the copper to lasers with wavelength of 1064 nm can be reduced from 95% to 15.5%. The process of copper laser welding with the thickness of 0.3 mm is studied by a 500 W fiber laser machine. The shape, strength and micro-hardness of the welding seam under different welding velocity and defocus amount are analyzed and the optimum parameters are found. Moreover, the laser welding quality of copper with black-treating is compared with that with graphite coating. The results show that the micro-hardness and strength of the welding seam of copper with black-treating are better than that with graphite coating.