Investigation on the improvement of mechanical and metallurgical behaviour of tungsten inert gas welded al 5052 h32 alloy using scandium added filler rod and friction stir process

Abstract

Aluminium alloys are widely used to fabricate structural newlinecomponents. Among Aluminium alloys and their family, Aluminium newlineMagnesium (Al-Mg) 5000 series alloys are commonly used for pressure newlinevessels, boilers, transportation, marine, and aviation structural application newlineowing to their good weldability, corrosion resistance, and recyclability. newlineWelding of Al-Mg alloy (5052-H32) is challenging and difficult due to the newlineinevitable problems such as evaporation of Mg, porosity, crack formation newlineduring weld pool solidification, loss of strain hardening effect, and coarse newlinemicrostructure in the weld fusion zone resulting in lower joint strength than newlinethe base metal. To overcome these issues, rare earth element Scandium (Sc) newlinewas added with filler material, and post treatment process was performed to newlineimprove the weldment properties. newlineIn this research work, Tungsten Inert Gas (TIG) welding was newlinesuccessfully used for welding 5 mm thick 5052-H32 aluminium alloy plates newlineutilizing ER5356 and 0.25 wt. % Sc added ER5356 filler rod. Further, the newlineeffect of the addition of Sc to the filler rod on the TIG welded joint with newlinemechanical and metallurgical behaviour was investigated. The Al-Sc newlineprecipitates are distributed uniformly throughout the fusion zone of scandium newlineadded weldment. The welded joint with scandium added filler rod has fewer newlineporosities, resulting in enhanced joint efficiency. Commercial filler rod newlinewelded joint had coarse microstructure, but Sc modified filler rod welded newlinejunction had fine dendritic structure. The physical characteristics of the newlineweldment were studied with the help of tensile strength and hardness tests. newline