(中國科學院金屬研究所 金屬腐蝕與防護國家重點實驗室，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化膜，確定了常溫稀土(鈰)化學轉化膜成膜工藝。應用電化學方法和浸泡試驗研究了鋁合金鈰化學轉化膜的成膜動力學及轉化膜在3.5%NaCl溶液中的耐蝕性能，并與傳統(tǒng)的Alodine處理工藝進行了比較。采用表面分析技術分析了膜的成分并觀察了膜的微觀形貌。結果表明，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轉化膜，能有效地抑制鋁合金的點腐蝕。SEM表明鋁合金鈰轉化膜由許多球形顆粒和塊狀膜構成。EDAX能譜表明，鈰轉化膜主要含有鈰、氧和鋁3種元素，球形顆粒含有較高濃度的氧和鈰。
關鍵字: 鋁合金； 轉化膜； 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
