(中國科學(xué)院金屬研究所 金屬腐蝕與防護(hù)國家重點(diǎn)實(shí)驗(yàn)室，沈陽 110016)
摘 要: 利用浸漬法在LY12鋁合金表面獲得了金黃色的鈰轉(zhuǎn)化膜，確定了常溫稀土(鈰)化學(xué)轉(zhuǎn)化膜成膜工藝。應(yīng)用電化學(xué)方法和浸泡試驗(yàn)研究了鋁合金鈰化學(xué)轉(zhuǎn)化膜的成膜動(dòng)力學(xué)及轉(zhuǎn)化膜在3.5%NaCl溶液中的耐蝕性能，并與傳統(tǒng)的Alodine處理工藝進(jìn)行了比較。采用表面分析技術(shù)分析了膜的成分并觀察了膜的微觀形貌。結(jié)果表明，本稀土處理工藝成膜工藝簡單，成膜速度快，耐蝕性能略優(yōu)于Alodine轉(zhuǎn)化膜，能有效地抑制鋁合金的點(diǎn)腐蝕。SEM表明鋁合金鈰轉(zhuǎn)化膜由許多球形顆粒和塊狀膜構(gòu)成。EDAX能譜表明，鈰轉(zhuǎn)化膜主要含有鈰、氧和鋁3種元素，球形顆粒含有較高濃度的氧和鈰。
關(guān)鍵字: 鋁合金； 轉(zhuǎn)化膜； 稀土； 耐蝕性
alloy in trivalent cerium solution
（State Key Laboratory for Corrosion and Protection, Institute of Metal Research,
The Chinese Academy of Sciences, Shenyang 110016, P.R.China）
Abstract:A golden yellow coating was obtained by immersion process on LY12 aluminum alloy surface. The process of cerium conversion coating at normal temperature was developed. The dynamics of coatings formation and its corrosion resistance in 3.5% NaCl solution were studied by electrochemical methods and immersion test, which was compared with traditional Alodine process. The microstructure of the coatings were investigated by scanning electronic microscopy (SEM), and the chemical composition of the coatings was analyzed. Experimental results show that the conversion process is simple and the speed of coatings formation is fast, and the corrosion resistance in 3.5%NaCl solution is sufficient, which is slightly superior to the coatings obtained by Alodine process and effectively inhibites the pitting corrosion of the aluminum alloy. SEM experiment shows that the coatings consist of lots of spherical particles and amounts of lumpish matrix. EDAX results show that the coatings consist of oxygen, cerium and aluminum, and the spherical particles contain higher concentration of cerium and oxygen than the other parts.
Key words: aluminum alloy; conversion coatings; rare earth metal; corrosion resistance
