Improving weld bead homogeneity in short arc GMAW processes applying low power diode lasers

Abstract

Using laser and arc power in equal parts, laser-arc hybrid welding processes are successfully adapted by the industry. This paper shows the stabilizing effects of diode lasers on short arc GMAW (gas metal arc welding) which deliver just a fraction of the supplied arc power. In a comprehensive comparison the stabilized and the sole GMAW processes are confronted and differences regarding process behavior and weld bead properties are pointed out. The tests were carried out with DC01 (1.0330) plates of 1 mm thickness deploying lasers using a mean laser intensity of 1,1 x104 W/cm2. Adding this low amount of intensity provides stability to the weld process and results in weld beads of higher homogeneity. The process behavior is characterized by the transient current and voltage curves which are analyzed in regards to consistency and uniformity. Metallographic analysis is employed to compare the weld bead dimensions at different energy ratios.