Investigations on copper welding using a frequency-doubled disk laser and high welding speeds

In this contribution laser welding of pure copper using laser light at the wavelength of 515 nm is discussed. Welds were analyzed with respect to the resulting penetration depth and the resulting quality. Heat conduction welding at high welding speed (> 1 m/s) is observed to be a stable process enabling reliable welds without spatter formation. In order to analyze the thresholds of fusing and evaporation high-speed images of the welding process were made. Analytically calculated threshold parameters were compared to the experimentally determined parameters, including an approach to deal with temperature-dependence of material properties. Furthermore, the transition zone between heat conduction welding and deep-penetration welding was investigated with respect to the resulting welding depth and weld seam width.