文章信息/Info

Title:

Effect of Heterogeneous Microstructure on Corrosion Resistance of AA2099-T8 Aluminum-Lithium Alloy and Its Anodic Films

作者:

麻彥龍

重慶理工大學材料科學與工程學院  重慶市模具技術重點實驗室

Author(s):

 MA Yanlong

Chongqing Municipal Engineering Research Center for Mould Technology ，School of Materials Science and Engineering，Chongqing University of Technology

關鍵詞:

鋁鋰合金; 微觀組織; 局部腐蝕; 陽極氧化

DOI:

10.7502/j.issn.1674-3962.2015.12.10

文獻標志碼:

A

摘要:

圍繞AA2099-T8合金，全面綜述了第三代新型鋁鋰合金在微觀組織、腐蝕行為及陽極氧化等方面取得的最新研究進展，重點分析了該合金的微觀組織對合金陽極氧化前后耐腐蝕性能的影響。研究發現：在3.5%NaCl溶液中，AA2099-T8合金上發生了亞穩態局部腐蝕和嚴重局部腐蝕兩類腐蝕，前者主要由Al-Fe-Mn-Cu-(Li)第二相顆粒引起，后者則與熱機械加工過程中的局部塑性變形及T1(Al2CuLi)相的非均勻析出有關。在酒石酸-硫酸陽極氧化（TSA）條件下，Al-Fe-Mn-Cu-(Li)第二相顆粒的陽極氧化行為明顯不同于鋁合金基體，破壞了陽極氧化膜的連續性，對陽極氧化處理合金的耐腐蝕性能產生不利影響。

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.