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The Gas Metal Arc Welding process (GMAW) is a highly productive process that can be used for joining a wide range of materials and sheet thicknesses due to its gap-bridging capability using its various process variants with different power output ranges. To ensure the economic efficiency of the GMAW-process, it can also be combined with other processes or auxiliary measures. Even laser radiation of low power and thus lower acquisition costs can influence an arc process, for example in its behaviour or the resulting weld. So far, only a few GMAW-process variants have been studied, meaning that the possibilities and limits of laser stabilization are not completely known. Therefore, in this thesis the laser stabilization at different GMAW-processes like the short arc, pulsed arc, spray arc and the electronically controlled short arc is investigated. One focus is the identification of the interactions between laser beam and gas metal arc as well as the resulting process behaviour and seam formation. For this purpose, the electrical signal behaviour as well as the arc and droplet transfer are analysed. Also, the different arrangement possibilities, conditions and settings of both the GMAW-process and the laser beam process are considered. The laser-stabilized GMAW-process, which uses relatively low laser beam power and intensity, is robust in handling and, especially in combination with the short arc, leads to a significant increase in deposition rates and welding speeds on joint welds. At the same time, the concept of laser stabilization can also be transferred to GMA-Brazing of steel sheets and used with metal powder filler wire electrodes. However, depending on the selected settings and materials, the additional laser beam can also have a destabilizing effect on the GMAW-process. In addition to a stabilizing effect, which can also be achieved in part by other arc parameters or process variants, the laser beam can also be used for guiding the molten pool, removing pores when joining galvanized steel sheets and changing the seam geometry, even at high welding speeds. |
