On the corrosion-induced mechanical degradation for different artificial aging conditions of 2024 aluminum alloy

In the present work, the effect of different artificial aging conditions of the Al 2024-T3 on the mechanical properties degradation due to corrosion exposure is studied. Different artificial aging conditions had been applied to tensile and fracture toughness specimens, which were subsequently exposed to exfoliation corrosion environment. Microstructure analysis showed that for the reference (T3) and peak-aged (PA) specimens the corrosion-induced surface pits were followed by formation of a microcrack network, while only large surface pits were noticed for the over-aged (OA) specimens. The tensile test results showed that the higher the (OA) condition, the lower degradation due to corrosion exposure the alloy has. Fracture toughness Kcr calculated on the basis of nominal thickness of the specimens confirms that the decrease due to corrosion is lower for the (OA) specimens. The Kcr values calculated on the basis of effective thickness of the specimens showed that the degree of decrease due to corrosion damage is negligible for the (OA) specimens. This phenomenon has been explained and discussed based on the resulting microstructure for the various aging conditions of the alloy.