Effects of a paraxial TIG arc on high-power fiber laser welding

In this study, the effects of a paraxial tungsten-inert gas (TIG) arc on the high-power fiber laser welding process were investigated by measuring plume behavior, plume temperature, weld depth, and the particles in the plume. The experimental results indicated that when DLA (i.e. the distance between the laser beam and arc) was less than 8 mm, the slender plume similar to the shape of the focused laser beam was eliminated, and the weld depth was increased by around 20%. Moreover, both the vertical and horizontal temperatures of the hybrid welding plasma were much higher than that of the plume. In addition, in the space near the laser beam, the size and density of the particles were significantly reduced. Further analysis indicated that the paraxial TIG arc could eliminate the slender plume by reducing the density and size of particles in the plume during high-power fiber laser-arc hybrid welding; therefore, it can reduce the negative effects of the plume on the welding process while improving laser energy utilization and the weld depth. (C) 2015 Elsevier Ltd. All rights reserved.