RESEARCH STATUS AND PROSPECTS FOR TIG-MIG HYBRID-ARC-WELDING TECHNOLOGY

Abstract

TIG-MIG hybrid welding integrates the merits of tungsten insert-gas welding (TIG) and metal inert-gas welding (MIG), and achieves a new material-joining process with high quality, high efficiency and low cost. However, TIG-MIG hybrid welding also had some shortcomings, such as a complex process, unstable arc, large heat input, limiting its application. To further improve and promote TIG-MIG hybrid welding, numerous universities and research institutes have put forward a series of improvement programs that achieve relatively good results. In this study TIG-MIG hybrid welding is discussed in three aspects: the welding-process improvement, welding-parameters optimization and numerical simulation of the welding process. It was found that the stability of the hybrid arc welding process and the quality of the weld bead can be improved by improving the current polarity, wire type and arc swing. The TIG current, the distance between the wire and tungsten, and the heat input had an important impact on the weld quality and the formation of defects. A numerical simulation of the welding process analyzed the effects of torch angle, the distance between the wire and tungsten, the welding speed and the temperature fields on the arc morphology, molten-pool behavior, and droplet transfer. According to the above analysis, it summarized the current research status of TIG-MIG hybrid welding, and then proposed future research directions based on the existing shortcomings and deficiencies.