Effect of Addition of Scandium in Filler Rod on Tungsten Inert Gas Welding of AA5052-H32 Alloy

Abstract

Tungsten Inert Gas (TIG) welding was used successfully to weld 5 mm thick aluminum alloy plates AA5052-H32 utilizing as and 0.25 wt % Sc added ER 5356 filler rod in this study. Furthermore, the effect of adding Sc to the filler rod on TIG welded joints with mechanical and metallurgical properties was investigated. An optical microscope (OM) and a scanning electron microscope (SEM) were used to examine the microstructures of the joints The Al-Sc precipitates are distributed uniformly throughout the fusion zone of scandium added weldment. The welded joint with scandium added filler rod has fewer porosities, resulting in enhanced joint efficiency. Commercial filler rod welded joints had a coarse microstructure, but Sc modified filler rod welded junctions had a fine dendritic structure. The welded joints’ tensile characteristics and hardness were investigated. Compared to commercial filler rods, the weld junction created with scandium enhanced filler rod has twice the ductility. SEM fractography revealed brittle fractures in weld samples with commercial filler rods and ductile fractures in weld samples with scandium-added filler rods. With the addition of Sc to the filler rod, no appreciable hardness difference was observed in the fusion zone. This study paper will aid companies and researchers to better understand the metallurgical and mechanical behaviour of TIG-welded AA5052-H32 plates using scandium added filler rod, reducing the number of experimental trials and allowing for further research.