Experimental Investigation on Micro-Welding of Thin Stainless Steel Sheet by Fiber Laser

Problem statement: The miniaturization of components plays an important role for manufacturing in electrical and electronic industries. The joining technology of thin metal sheets has been strongly required. Laser welding with micro-beam and high-speed scanning is a promising solution in micro-welding, because it has high-potential advantages in welding heat sensitive components with precise control of heat input and minimal thermal distortion. Approach: In this study, the characteristics of laser micro-welding of thin stainless steel sheets by using a single-mode CW fiber laser with high-speed scanning system were experimentally investigated. Results: It was clarified that the welding bead width and depth increased with increasing the scanning velocity under a constant energy density condition and high efficient welding was expected by using high-speed laser scanning with Galvano scanner. The utilization of shielding gas was very effective to obtain smooth fusion bead and the combination of micro beam spot and high-speed laser scanning made it possible to obtain good overlap welding of ultra-thin stainless steel sheets. Conclusion: A faster and high quality welding could be achieved by using a single-mode fiber laser with micro-beam and high-speed scanning.