Electric evaluation of hybrid laser-TIG welding: Interaction between arc and laser plume

Hybrid laser-arc welding (HLAW) is regarded as a promising joining process, since it can compensate disadvantages from laser autogenous welding and arc welding by uniting both techniques into a single melt pool. Such a process can achieve relative high quality metallurgical bonding, high speed, and low deformation. However, the process is considered complex and of difficult parametrization, as the four states of matter come to coexist in the same space and as the union of two processes generates interactions that are still not well understood [C. Churiaque, M. Chludzinski, M. Porrua-Lara, A. Dominguez-Abecia, F. Abad-Fraga, and J. Maria Sánchez-Amaya, “Laser hybrid welding of large thickness naval steel,” Metals J. 9, 100 (2019); G. Casalino, Hybrid Laser Welding: A Review, DAAAM International Scientific Book (DAAAM International, Vienna, 2010), Chap. 38, pp. 413–430; and B. Ribic, T. A. Palmer, and T. DebRoy, “Problems and issues in laser-arc hybrid welding,” Int. Mater. Rev. 54, 223–244 (2009)]. One of HLAW’s main variations is studied and evaluated in this work, the hybrid laser-Tungsten Inert Gas (TIG) welding process. In this process, the interaction between the arc and the laser-induced plume is dependent on the shielding gas flow, arc welding current and voltage, laser beam characteristics, and the geometric relations between electrode, laser incidence position, and workpiece. Here, in order to further analyze the influence of the laser power on arc behavior during the hybrid process, tests were performed by varying the TIG current and laser power parameters from 60 to 100 A with increments of 20 A and 0 to 2500 W with increments of 500 W, respectively. From an arc’s voltage monitoring, one can analyze the influence of the interaction between the arc’s plasma and the plume induced by the laser. It was observed that the perturbation generated by the laser beam is directly proportional to its power, as there is an increase in the average voltage and the perturbance amplitude as a function of the applied laser power. The analysis presented over the dynamic aspect of the hybrid welding process and the influence of the laser beam on the arc contribute to the laser-TIG welding consolidation within the academic and industrial scenario.