Abstract
TIG and MIG welding are most popular gas shielded arc welding processes used on many industrial fields. MIG welding is high efficiency process compared to TIG welding, however it is needed to improve the quality about spatter and weld metal toughness for advanced GMA process. Although pure Ar shielding gas is desirable for weld metal toughness, MIG arc is unstable in pure Ar shielded condition due to the irregularly behavior of cathode spot on plate surface and suitable welding execution is difficult. We found that MIG arc becomes stable even though in pure Ar shielded condition by simple hybridization of TIG and MIG. Therefore, this process has high possibility as new type of high quality and high efficiency welding process. In this study, we investigated the influence of hybridization condition such as TIG-MIG current balance, distance between the both arcs and torch angles on stabilization of the process and confirmed the suitable range of the condition. The main results are as follows: (1) TIG current is needed to be larger than MIG current for stabilization of MIG arc. (2) According to increase of the distance between the both arcs, MIG arc shows high arc voltage and becomes unstable. (3) On the condition of small angle between the both torches, as thirty degree, MIG arc is deflected toward back by repulsion with TIG arc and bead shape becomes convex.
