Abstract:
The Tungsten Inert Gas-Metal Inert Gas (TIG-MIG) hybrid process has the combined
advantages of standalone TIG and MIG welding processes. This study investigates the thermal
distribution of the TIG-MIG hybrid welding process compared to the standalone TIG and MIG
welding processes. The welds' mechanical properties, microstructural evolution, and phase
formation are also discussed. The process parameters for the TIG-MIG, TIG and MIG welding
processes used in this study were obtained from prior parametric optimisation for each welding
process performed by the Taguchi method with an L-9 orthogonal matrix. The thermal
behaviour of TIG, MIG and TIG-MIG welds were investigated by adopting the Gaussian heat
source model on the ANSYS workbench. The simulated temperature distributions of the three
weld types were validated by the mechanical, microstructural, and phase formation
characteristics as obtained experimentally. Similar temperature profiles were observed for all
weld types having peak temperatures at the weld seams. The simulated temperature
distributions were in good correlation with the experimentally obtained from the hardness
results, microstructural evolution and phase formation, as revealed from the X-ray diffraction
analysis. Hence, the Gaussian heat source model can accurately simulate the properties of a
complex heat source interaction, allowing for process optimisation and forecasting
