A-TIG (activated flux tungsten inert gas) welding: - A review

TIG welding faces low weld penetration as the major challenge which ultimately limits the productivity of the process. To mitigate this challenge and utilize the peerless benefits of TIG welding, a technique known as Activated flux tungsten inert gas (A-TIG) welding has been developed and is being widely researched upon. In this process, a layer of flux is applied over the surface of workpiece prior to welding. A-TIG is very well capable of increasing the weld penetration depth by almost three times or even more and aspect ratio around 200%, in comparison to conventional TIG welding. This feature of A-TIG pushes its potential to be of more practical use in manufacturing industries requiring high productivity and fine weld quality. Such high depth of penetration is explained with the help of several mechanisms stated by various researchers. The inclusion of different fluxes and the amount of oxygen present in the molten pool zone also plays a major role in A-TIG. A significant change in the mechanical properties and microstructure of weld bead is observed by the effect of enmeshed oxides. Apart from having notable proficiency, this process did not receive enough attention and appreciation which sets up the motion for writing this review paper, discussing A-TIG welding for different metals, welding flux with its chemical composition and various process parameters in detail. The resulting effects of different activated fluxes on mechanical properties and metallurgical aspects like weld pool attributes, weld chemistry and HAZ microstructure, material dilution, slag reactions and mainly weld penetration has been clarified in the study. (C) 2021 Elsevier Ltd. All rights reserved.