Influence of arcs interaction on TIG-MIG hybrid welding process

Abstract

Considering Biot-Savart law, the models for arcs interaction during Tungsten inert gas-metal inert gas (TIG-MIG) hybrid welding process are improved. Base on the adaptive current density mathematical model of inclined arc, the heat-force models for TIG-MIG hybrid welding are established to study the interacting forces between TIG and MIG arcs by analyzing the distribution of heat flux and weld formation. The inclined angles of two arcs under different welding currents are also calculated. The results indicate that the repelling force between two arcs could increase verticality of TIG arc, which will develop the heat density of TIG arc. And the behavior of MIG energy is the main factor of bead forming process during TIG-MIG hybrid welding. Then the effect of distance between TIG and MIG torches and their relative front or back position on welding process is estimated. It is found that TIG leading in TIG-MIG hybrid welding is beneficial to stabilize the welding process. Good agreement is observed between numerical predictions and experimental data, the results show that these numerical models can reflect TIG-MIG hybrid welding process well and can be used to optimize its welding parameters.