Comparison study of 6082 Al alloy laser welding using 455 nm blue laser and 1080 nm near-infrared laser

When using near-infrared (NIR) laser with wavelength around 1000 nm to weld Al alloys, the high laser reflectivity of Al alloys prevents most of the laser energy from participating in welding. While, the shorter wavelength laser can provide better absorption rate for Al alloys. The welding experiments of 6082 Al alloy using 455 nm wavelength blue laser and 1080 nm wavelength NIR laser were systematically studied. By analyzing the macroscopic morphology, infrared thermography, microstructure and mechanical properties of the welds, the special physical phenomenon of blue laser in the welding process, and the characteristics of two different wavelengths of laser welding 6082 alloy were studied. Results showed that the depth and width of weld welded by blue laser were greater than those welded by NIR laser. Meanwhile, the grains of the blue laser weld were fine, and the mechanical properties of the weld welded by blue laser was almost equal to that of NIR laser. Finally, the effects of different wavelengths of laser heat sources on the microstructure and mechanical properties of the joints were mainly studied.