Fundamental study on welding properties of 515nm green laser

Compared with lasers with the wavelength of 1030nm∼1080nm, including Nd:YAG, Fiber and Disk lasers, one of the advantages of using 515 nm green laser is its higher absorption for many metals, except aluminum. Thus deeper penetration depth is expected for welding of these metals. In this paper, the basic phenomena and penetration properties of 515nm green laser was investigated. A 515nm green laser with the maximum power of 300W and a 1070nm-1080nm fiber laser with the maximum power of 2000W were separately used for conducting welding experiments. The materials used in welding were pure copper and 304-Type stainless steels. A high-speed camera was used to observe the behavior of the plume and weld pool during welding. The results show that the green laser can produce extremely deep and narrow weld bead. The mechanism of welding keyhole with 515nm green laser is discussed as well.