Evaluation of the TIG–MIG/MAG welding process in direct polarity

Abstract

The associations of tungsten inert gas (TIG) and metal inert gas/metal active gas (MIG/MAG) welding process intends to take advantage of the higher productivity of the MIG/MAG process with the greater heat control imposed by the TIG process. In this context, the present study aims to evaluate the effects of the TIG–MIG/MAG process with both electrodes in direct (negative) polarity in weld bead geometry. A pioneering research on TIG–MIG/MAG process was carried out for the purpose of writing this article. Therefore, weld beads were made by the conventional MIG/MAG process and by the TIG–MIG/MAG process. Two input parameters, the MIG/MAG polarity and the TIG current, were evaluated. The output responses such as bead width, reinforcement, penetration, melted area, and convexity angles were evaluated. Macrographs were performed to measure the geometrical parameters of the weld bead. The results of these measurements were evaluated by a variance analysis. The results show that the polarity variation has an influence to modify the weld bead geometry in a TIG–MIG/MAG welding process. It was also noticed that the insertion of TIG current caused the tendency to greater wettability, penetration, melted area, width, and smaller reinforcements of weld beads.