镁合金表面磷化／溶胶凝胶复合膜的制备及其耐蚀性  

Preparation and Corrosion Resistance of Phosphating Sol-Gel Composite Coatings on Magnesium Alloy

作　　者：尚伟[1] 温玉清[1] 司延举 王旭峰[1] 姜吉琼[1] 

机构地区：[1]桂林理工大学广西矿冶与环境科学实验中心,广西桂林541004 [2]许继集团有限公司,河南许昌461000

出　　处：《表面技术》2014年第2期95-99,共5页Surface Technology

基　　金：广西矿冶与环境科学实验中心资助项目(KH2012ZD002);桂林理工大学博士科研启动项目(002401003351)~~

摘　　要：目的结合磷化与溶胶凝胶工艺,在AZ91镁合金表面制备磷化/溶胶凝胶复合膜。方法先对镁合金进行磷化处理,再多道涂覆SiO2溶胶凝胶层,通过正交试验结合电化学分析方法,优化溶胶凝胶层涂覆工艺,并分析磷化/溶胶凝胶复合膜的表面微观形貌和耐蚀性。结果溶胶凝胶层的优化沉积工艺如下:TEOS,TEOH,H2O,HCl体积比为28∶20∶10∶0.35,凝胶温度30℃,凝胶时间5 min,涂覆6次。在优化条件下所制备的复合膜结合力好且光滑,有少许微裂纹,与镁合金基体和磷化膜样品相比,其腐蚀电流密度最小,电化学阻抗最大。结论磷化/溶胶凝胶复合膜提高了镁合金的耐蚀性。Objective The composite coatings were prepared on AZ91 magnesium alloy using the phosphate and sol-gel process. Methods Magnesium alloy was phosphatized, then coated with multiple SiO2 sol gel layers. Using the orthogonal experiment combined with electrochemical analysis method, we optimized the deposition process conditions of the sol gel film, and analyzed the sur- face microstructure and corrosion resistance of the composite coatings. Results The results showed that the optimized deposition process conditions of the sol gel film were as follows： volume ratio of sol formula （TEOS ： TEOH ： H20 ： HC1） 28 ： 20 ： 10 ： 0.35, gel temperature 30 ~C, gel time 5 min, coating times 6. Under the optimal condition, the composite coating was smooth, with a few micro cracks and good binding force. Compared with the magnesium alloy substrate and phosphate coating, the corrosion current density of the composite coating was the lowest, and the electrochemical impedance was the largest. Conclusion The corrosion resistance of magnesium alloy was improved by phosphating sol-geI composite coating.

关 键 词：镁合金 磷化膜 溶胶凝胶 复合膜层 耐蚀性 

分 类 号：TG174.45[金属学及工艺—金属表面处理]