Effect of corrosion exposure on aluminum alloy 2024 for different artificial ageing conditions

Abstract

The present work investigates the corrosion behaviour of AA2024 in two different conditions, named T3 and Peak-Ageing (PA), respectively. Tensile specimens were artificially aged up to the PA condition, subsequently corroded for different exposure times to exfoliation corrosion solution and then they were immediately tensile tested. The corrosion exposure seems to essentially affect the mechanical behaviour of the specimens in T3 condition while this was not the case for the specimens in PA condition. After only 2 h corrosion exposure time, almost 23 % decrease in elongation at fracture for AA2024-T3 was noticed, while less than half of this decrease was evident in the PA condition for the same corrosion exposure. For higher exposure times (> 24 h), specimens at PA condition exhibited lower corrosion-induced decrease in tensile ductility, thus implying that surface deterioration mechanism change with artificial ageing of heat-treatable aluminium alloys.