文章信息/Info

Title:

Effect of heterogeneous microstructure on corrosion resistance of the new-type aluminum-lithium alloy AA2099-T8

作者:

麻彥龍1; 2

1. 重慶理工大學(xué)材料科學(xué)與工程學(xué)院
2. 重慶市模具技術(shù)重點(diǎn)實(shí)驗(yàn)室（重慶理工大學(xué)）

Author(s):

Ma Yanlong 1;  2

關(guān)鍵詞:

鋁鋰合金; 微觀組織; 局部腐蝕; 陽(yáng)極氧化

文獻(xiàn)標(biāo)志碼:

A

摘要:

綜述了第三代新型鋁鋰合金在微觀組織、腐蝕及陽(yáng)極氧化方面的最新研究進(jìn)展，重點(diǎn)分析了AA2099-T8合金的微觀組織對(duì)合金陽(yáng)極氧化前后耐腐蝕性能的影響。研究發(fā)現(xiàn)：在3.5%NaCl溶液中，AA2099-T8合金上發(fā)生亞穩(wěn)態(tài)局部腐蝕和嚴(yán)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，而后者則與熱機(jī)械加工過(guò)程中的局部塑性變形及T1(Al2CuLi)相的非均勻析出有關(guān)；在酒石酸-硫酸陽(yáng)極氧化（TSA）條件下，Al-Fe-Mn-Cu-(Li)第二相顆粒的陽(yáng)極氧化行為明顯不同于鋁合金基體，結(jié)果破壞了陽(yáng)極氧化膜的連續(xù)性，進(jìn)而對(duì)陽(yáng)極氧化處理合金的耐腐蝕性能產(chǎn)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.