Comparative Evaluation of Fatigue and Corrosion Characteristics of Metal Inert Gas Welded AA6061‐T6 Aluminum Alloy Joints

ABSTRACT AA6061 aluminum alloy joints were produced utilizing various metal inert gas (MIG) welding techniques, including constant current metal inert gas welding (CC‐MIG), pulsed current metal inert gas welding (PC‐MIG), cold metal transfer (CMT‐MIG) and pulsed cold metal transfer (PCMT‐MIG). The investigation into the high‐cycle fatigue performance of MIG welded AA6061 alloy joints is crucial due to their extensive use in components subjected to repeated stress over long periods. However, owing to the association of welding with the dissolution and breakdown of intermetallics, which is particularly severe in high‐energy consumption processes, aluminum alloy joints are highly susceptible to corrosion. The weld metal region of PCMT‐MIG joints exhibited higher corrosion potential ( E corr ) values and lower current density ( i corr ) values compared to the other joints. This significantly improves both fatigue life and corrosion resistance compared to traditional methods, offering up to 8% longer fatigue life and reducing corrosion rates by 94.8%. This is due to the stirring action of the filler wire that results in a narrow softening zone and less number of sites for crack initiation.