(哈爾濱工業(yè)大學材料科學與工程學院， 哈爾濱 150001)
摘 要: 利用浸漬法在2024鋁合金表面上獲得了金黃色的稀土轉(zhuǎn)化膜， 確定了成膜的最佳工藝條件。 利用濕熱試驗、 鹽水浸漬試驗等實驗方法評價了膜的耐蝕性能， 并和傳統(tǒng)的MBV法及Alodine法進行了比較。 結(jié)果表明， 稀土轉(zhuǎn)化膜的耐蝕性能優(yōu)于MBV轉(zhuǎn)化膜， 與Alodine轉(zhuǎn)化膜接近。 利用電化學方法研究了稀土轉(zhuǎn)化膜的耐蝕機理， 膜的存在同時抑制了腐蝕過程中的陰極反應和陽極反應，使腐蝕的動力消失。 利用掃描電鏡觀察了膜的微觀形態(tài)， 膜是由大小不同的球狀顆粒組成， 大的顆粒之上夾雜或附著小的顆粒， 膜的形成包含一個晶粒的形成和長大的過程。 稀土轉(zhuǎn)化膜處理工藝簡單，對環(huán)境無污染， 膜的耐蝕性強， 具有一定的應用前景。
關鍵字: 稀土轉(zhuǎn)化膜 耐蝕性 微觀形態(tài) 成膜機理 耐蝕機理
COATING ON ALUMINUM 2024
（School of Materials Science and Engineering,Harbin Institute of Technology, Harbin 150001, P. R. China
）
Abstract:A golden conversion film was obtained on the surface of aluminum alloy 2024 by immersion process. The suitable conditions of technology were established. The anticorrosive property of the conversion film was examined intensively by moisture/heating test, salt solution immersion test. Compared with otherconversion coatings, the anticorrosive property of REM conversion coating is significantly superior to that of MBV conversion film and similar to that of anodizing coating. The mechanism of corrosion resistance of the film was studied by electrochemical method. The result showed that both anodic and cathodic reaction of corrosion were reduced by the exisiting film, thus the motivation of corrosion was decreased. The microphotography of the film was studied by scanning electron microscopy, which show that the film consists of different size of spherical particles,the bigger particles are dotted with smaller ones. The formation of the film consists of two steps: the formation and growth of the particles. This protection scheme is very simple, nontoxic, the film pocesses high anticorrosive property, the result is very encouraging.
Key words: REM conversion coating anticorrosive property microstructure mechanism of formation mechanism of corrosion resistance
