The Effect of Current, Cr2O3 and MnO2 Active Flux to The Depth of Penetration and Microstructure of A-TIG 5083 Aluminium Welding

Abstract

Materials with a thickness exceeding 5 mm require at least two layers of TIG welding; however, this challenge can be addressed through A-TIG welding. A-TIG welding utilizes an active flux to increase penetration without requiring changes to welding parameters. This research investigated the effects of current intensity and the use of Cr₂O₃ and MnO₂ active fluxes on depth of penetration, microstructure, and hardness. The study employed A-TIG welding on 5083 aluminum with current variations of 100 A, 130 A, and 160 A. Results indicated that Cr₂O₃ active flux at a current of 160 A achieved the deepest penetration of 5.7 mm, while MnO2 at 100 A yielded the highest average hardness of 77.96 kgf/mm². Regarding microstructure, no significant changes were observed in the base metal across both fluxes; however, grain growth in the weld metal was more pronounced than in the Heat Affected Zone (HAZ) and base metal. Ultimately, Cr₂O₃ provided greater depth of penetration and a more dispersed distribution of Mg₂Si precipitates, whereas MnO₂ demonstrated a superior effect on hardness compared to Cr₂O₃.