C_3H_8O_3含量对AZ91D镁合金微弧氧化过程及膜层特性的影响  

Influences of C_3H_8O_3 Concentration on Formation and Characteristics of MAO Coatings on AZ91D Magnesium Alloy

作　　者：王淑艳[1,2] 夏永平[1] 刘莉[1] 

机构地区：[1]江苏科技大学材料科学与工程学院,镇江212003 [2]江苏科技大学江苏省先进焊接技术重点实验室,镇江212003

出　　处：《中国腐蚀与防护学报》2013年第3期235-240,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：江苏高校优势学科建设工程资助项目(12504230006)

摘　　要：在含有不同C3H8O3含量的硅铝复合电解液中,利用交流脉冲电源在AZ91D镁合金基体上制备了一系列微弧氧化膜。利用SEM和膜层测厚仪分别研究了陶瓷膜层的微观形貌特征及厚度,采用全浸泡实验和电化学阻抗谱测试了膜层在3.5%NaCl中性溶液中的耐蚀性能。结果表明,微弧氧化过程中的起弧电压和终止电压均随C3H8O3含量的增加而呈上升的变化趋势。随着C3H8O3含量的增加,膜层耐蚀性先提高后降低,而膜厚变化幅度不大。膜层的耐蚀性主要取决于内部致密层,当C3H8O3含量为5 mL/L时,膜层相对较致密,因而表现出良好的耐蚀性能。Microarc oxidation （MAO） coatings were obtained on the AZ91D magnesium alloy by AC pulse electrical source in a silicate-aluminate based composite electrolyte containing various concentrations ofC3H8O3. The morphologies and thickness of ceramic coatings were characterized by SEM and layer thickness meter, respectively. The corrosion resistance of coatings in a 3.5% NaCl neutral solution was evaluated by the immersion test and electrochemical impedance spectroscopy （EIS）. The results showed that the striking voltage and final voltage increased gradually with the increase of C3H8O3 concentration during the MAO process. With the increase of C3H8O3 concentration in the electrolyte, the corrosion resistance of the coatings increased at first and then decreased gradually, however, the variation of the coating thickness was not obvious. The EIS results showed that the corrosion resistance of the coatings was influenced by the inner dense layer. The coating exhibited better corrosion resistance in the electrolyte containing 5 mL/LC3H8O3 due to its relatively compact microstructure.

关 键 词：镁合金微弧氧化C3H8O3 耐蚀性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]