Study for TIG–MIG hybrid welding process

Tungsten inert gas (TIG) and metal inert gas (MIG) welding are the most popular gas-shielded arc-welding processes used in many industrial fields. MIG welding is a high-efficiency process compared to TIG welding. However, improvements are needed to reduce spatter and improve weld metal toughness. Although pure argon shielding gas is desirable for weld metal toughness, MIG arcs are unstable in pure Ar to the extent that executing welding is difficult. We have found that MIG arcs become stable even using pure argon by simply using a hybrid TIG and MIG system. This process has the possibility of becoming a new welding process giving high quality and efficiency. In this study, we investigate the influence of the balance of current between the TIG and MIG arcs, which is most important in determining arc stability and arc penetration. We have confirmed the suitable range of conditions both experimentally and through numerical simulation and have applied this process for butt and fillet joints. We show that the welding time can be reduced to 17 ~ 44 % of the time required using a conventional TIG process.