高锰酸盐对镁合金表面磷化膜形貌和防护性能的影响  

Effects of Permanganate Anions on Surface Morphology and Corrosion Resistance of Phosphate Conversion Coatings on AZ91D Magnesium Alloy

作　　者：周虎亮 周勇[1] 陈钇江 黄成敏 张恒 熊金平[2] 闫福安[1] ZHOU Hu-liang;ZHOU Yong;CHEN Yi-jiang;HUANG Cheng-min;ZHANG Heng;XIONG Jin-ping;YAN Fu-an(Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan 430073, China; Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing 100029, China)

机构地区：[1]武汉工程大学绿色化工过程教育部重点实验室,湖北武汉430205 [2]北京化工大学材料电化学过程与技术北京市重点实验室,北京100029

出　　处：《材料保护》2018年第10期84-87,共4页Materials Protection

基　　金：武汉工程大学校长基金(20170601)资助

摘　　要：为了进一步研究磷化液中KMnO。成分对镁合金表面磷化膜形貌和防护性能的影响程度，在不同KMnO。含量的磷化液中制备了一系列磷化膜。通过观察膜的宏观形貌和CuSO。点滴试验优化了KMnO。的含量；采用电化学阻抗谱（EIS）和动电位极化曲线对磷化膜的防护性能进行了评价。结果表明：磷化膜宏观形貌佳、点滴液变色时间最长的KMnO。含量是0．10g／L；在硼酸缓冲液中添加0．10g／LKMnO。所制备磷化膜的膜层电阻（Re）和电荷转移电阻（Re）显著大于未添加KMnO4时的值；腐蚀电位（Ecorr）和腐蚀电流密度（Jcorr）较未添加KMn04磷化膜的有明显的正移和减小，0．10g／LKMnO。含量最有利于增强磷化膜对镁合金的防护作用。In order to investigate effects of the addition of KMnO4 into the phosphating solution on the surface morphology and corrosion resistance of the phosphate coatings, the phosphate coating containing KMnO4 was prepared. The appropriate content of KMnO4 in the treatment bath was optimized with macro-morphology observation and CuSO4 color test, and the corrosion resistance of phosphate coatings was evaluated with electrochemical impedance spectroscopy （EIS） and potentiodynamic polarization curve. Results showed that the optimal content of KMnO4 in the treatment bath was 0.10 g/L, resulting in that the coating had the best macro-morphology and the longest time of color change. In borate buffer solution, the coating resistance （ Re ） and electron transfer resistance （ Rct ） of the phosphate coatings with the addition of 0. l0 g/L KMn04 were greater that those without the addition of KMn04; at the same time, the corrosion potential （Ecorr） and the corrosion current density （ Jcorr ） were more positive and lower than those without the addition of KMn04, respectively. This indicated that the addition of perman- ganate anions was beneficial to the improvement of corrosion resistance for phosphate coatings.

关 键 词：镁合金磷化 高锰酸盐 耐蚀性 电化学行为 

分 类 号：TG174.45[金属学及工艺—金属表面处理]