Effects of aging treatment and peripheral coarse grain on the exfoliation corrosion behaviour of 2024 aluminium alloy using SR-CT

• Published in: Journal of materials research and technology Vol. 9; no. 3; pp. 3219 - 3229
• Main Authors: Sun, Shuangqing, Fang, Yi, Zhang, Le, Li, Chunling, Hu, Songqing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2020; Elsevier
• Subjects: 2024 aluminium alloy; Aging treatment; Exfoliation corrosion; Peripheral coarse grain (PCG); SR-CT; Exfoliation corrosion; SR-CT; 2024 aluminium alloy; Aging treatment; Peripheral coarse grain (PCG)
• ISSN: 2238-7854
• DOI: 10.1016/j.jmrt.2020.01.069

The exfoliation corrosion behaviour of 2024 aluminium alloy was investigated through exfoliation corrosion test, together with synchrotron radiation X-ray computed tomography (SR-CT) to achieve the 3D segmentation of precipitated phases, cracks and corrosion products. The results demonstrate that aging treatment has a significant effect on the distribution of the precipitated phases in the 2024-T4 aluminium alloy, and the precipitated phases continuously distributed along the grain boundary would lead to intergranular corrosion (IGC) which is easily evolved into exfoliation corrosion. In the 2024-T2 aluminium alloy, the longest crack was found to locate at the boundary between the inner grains structure and outer peripheral coarse grain (PCG) structure, which indicates that the corrosion is attributed to electrochemical property difference of two structures.