Chongqing Municipal Engineering Research Center for Mould Technology ,School of Materials Science and Engineering,Chongqing University of Technology
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DOI:
10.7502/j.issn.1674-3962.2015.12.10
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Abstract:
State-of-the-art research progress on microstructure,corrosion resistance and anodizing behavior of the third generation aluminum-lithium alloys has been reviewed,with particular focus on the effect of microstructure on corrosion resistance of the new-type aluminum-lithium alloy AA2099-T8 before and after anodizing. It was found that two types of localized corrosion occurred in the alloy in 3.5% NaCl solution, namely metastable localized corrosion and severe localized corrosion. The metastable localized corrosion is ascribed to Al-Fe-Mn-Cu-(Li) constituent particles while the severe localized corrosion is associated with localized plastic deformation and heterogeneous precipitation of the T1(Al2CuLi) phase. During tartaric-sulphuric acid anodizing (TSA),the Al-Fe-Mn-Cu-(Li) constituent particles behaved differently compared with the alloy matrix,leading to the formation of discontinuities in the anodic film,which deteriorates the corrosion resistance of the anodized alloy.