Development and experimental investigation of a novel filler material for MIG welding of AA7075-T6 aluminum alloy for aerospace application

AA7075-T6 aluminum alloy is commonly employed in the aerospace industry owing to its superior strength-to-weight ratio and outstanding mechanical characteristics. However, its poor weldability, especially when using conventional fusion welding techniques, poses significant challenges, often leading to hot cracking, porosity, and loss of mechanical strength in the heat-affected zone (HAZ). This study presents an experimental investigation into the Metal Inert Gas (MIG) welding of AA7075-T6 using a novel filler material (Scandium (Sc)), designed to enhance weld quality and mechanical performance. The novel filler, formulated to reduce hot cracking susceptibility and improve metallurgical compatibility, was evaluated through a series of welding trials under controlled parameters. Post-weld assessments, including mechanical properties like tensile strength and micro-hardness, were conducted to evaluate qthe performance of the welded joints. The results showed that incorporating Al-Sc filler material in MIG welding led to a refined microstructure with a notable improvement in mechanical properties, with micro-hardness and tensile strength increasing by 6.3% and 10.7%, respectively. These findings highlight the significant potential of this welding approach for use in aerospace structures. Its demonstrated strength and reliability make it particularly suitable for applications where structural integrity and performance are critical.