Microstructure Evolution and Mechanical Properties of 2219 Aluminum Alloy A–TIG Welds

The effects of three activating fluxes, SiO2, TiO2, and MoO3, in tungsten inert gas (TIG) welding process on penetration, morphology, and mechanical properties of weld joint were investigated by bead on plate welding on 2219 aluminum alloy. Experimental results showed that a noticeable increase in the weld penetration and depth to with ratio was obtained by using activating fluxes. Among all the activating fluxes used in this study, the maximum penetration was achieved in case of SiO2 flux. The microstructure analysis demonstrated that oxide fluxes can promote transition from columnar to equiaxed grain growth in the fusion zone. It is also found that A–TIG weldments exhibit superior mechanical properties including tensile strength and hardness than those of TIG welding without flux.