Solvent-Driven Flux Deposition Behavior and Weld Pool Response in A-TIG Welding of Aluminum 5083-H116

Abstract:

Activated Tungsten Inert Gas (A-TIG) welding is widely used to enhance penetration in aluminum alloys; however, inconsistent weld performance is often reported even when similar active-flux chemistries are applied. This indicates that factors beyond flux composition alone influence weld stability, highlighting the importance of understanding flux delivery during welding. The scientific objective of this study is to clarify how solvent characteristics govern active-flux transport, surface retention, and weld pool response in A-TIG welding of Aluminum 5083-H116. Rather than optimizing flux chemistry, this work focuses on isolating the solvent effect using a TiO₂–SiO₂ active-flux system dispersed in methanol–isopropanol solvent mixtures. A-TIG welding experiments were carried out under identical welding parameters and flux chemistry, while varying the solvent composition. Weld penetration depth, penetration-to-width ratio, microhardness distribution, and grain structure were evaluated to assess the metallurgical response. The results show that solvent composition significantly influences penetration behavior, with penetration depth varying from approximately 3.5 mm to 5.0 mm and the penetration-to-width ratio increasing by up to 30% under more stable solvent conditions. Microhardness in the weld metal ranged between 70 and 90 HV, accompanied by observable differences in grain morphology. More stable flux retention associated with methanol-rich solvent mixtures produced smoother penetration profiles and finer, more uniform grains, whereas higher isopropanol content tended to result in less stable penetration and coarser grain structures. These findings provide new understanding that solvent selection plays a governing role in A-TIG welding by controlling flux transport and arc–pool interaction. The study extends conventional flux-centric A-TIG knowledge and offers a practical framework for improving weld stability and reproducibility in aluminum alloy welding through solvent-controlled flux delivery.

• Periodical: Materials Science Forum (Volume 1195)
• Pages: 69-75
• DOI: https://doi.org/10.4028/p-eQ9KGy
• Online since: June 2026
• Authors: Wisnu Yulianto Nugroho, Yusuf Eko Nurcahyo*, Pongky Lubas Wahyudi, Dian Setiya Widodo, Ahmad Jabir
• Keywords: Aluminum 5083-H116, A-TIG Welding, Flux Transport, Solvent Effect, Weld Pool Response

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