Manipulating the melt propagation of short arc gas metal arc welding with diode lasers <1 kW for improvement in flexibility and process robustness

Abstract

The processes that were performed for the studies on manipulating the melt propagation of the short arc gas metal arc welding process were carried out with a diode laser emitting with mean intensities of maximum 1.1 × 104 W/cm2 and a wavelength of 1025 nm on 1.0330 low carbon steel with a thickness of 1 mm. To determine the ability of the laser to manipulate the melt, investigations in terms of static displacement and dynamic movement of the laser beam via a scanner optic were executed. By displacing the laser spot statically and parallel to the weld, the shape of the bead can be influenced, and furthermore misalignments of fillet welded sheets up to 3 mm can be compensated. The extent of displacement and the influence of the laser energy on the weld bead geometry were examined through metallographic analysis regarding the width and height of the beads as well as the shift in position. The use of a two-dimensional scanner optic adds the potential of moving the melt in nonlinear shapes. The high speed camera footage is examined to visualize the melt dynamics in displacement operation. For comparing the weld properties of weld beads with and without laser stabilization in static and dynamic operations, the transient current and voltage curves are recorded and evaluated regarding alterations of the mean values.