Corrosion behavior of aluminum alloys in harsh marine atmospheric environment

Purpose This study aims to systematically investigate the corrosion behavior of AA1050, AA2024, AA5052, AA6061 and AA7075 in the marine atmospheric environment of Sanya, Hainan. Design/methodology/approach A four-year outdoor exposure test was conducted, and various characterization techniques, including scanning electron microscopy, three-dimensional laser confocal microscopy and X-ray diffraction, were used to analyze the corrosion morphology, corrosion product composition and their impact on the matrix material. Findings The results show that all five aluminum alloys exhibited pitting corrosion, with AA2024 and AA7075 further experiencing exfoliation corrosion, which subsequently led to intergranular corrosion. This form of corrosion significantly accelerated the corrosion rate of the alloys, closely related to the second phases rich in Cu and Zn in AA2024 and AA7075. Originality/value This study aims to provide scientific basis for the protection of aluminum alloys in marine atmospheric environments and crucial insights into the durability of aluminum alloys in marine environments.