Study on Copper Surface Pre-Treating and Welding with Fiber Lasers

Abstract

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.