硅酸钠浓度对ME21镁合金微弧氧化膜微观结构及耐蚀性的影响  

Effect of the concentration of sodium silicate in electrolyte on microstructure and corrosion resistance of microarc oxidation film on ME21 magnesium alloy

作　　者：韩帅 卢艳青[1] 张新禹 朱白林 魏双磊 苏俊豪 刘岱宗 HAN Shuai;LU Yanqing;ZHANG Xinyu;ZHU Bailin;WEI Shuanglei;SU Junhao;LIU Daizong(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051

出　　处：《电镀与涂饰》2023年第8期12-17,共6页Electroplating & Finishing

摘　　要：采用微弧氧化(MAO)技术在含锰和稀土的ME21镁合金表面制备陶瓷膜层。通过扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学工作站研究了电解液中硅酸钠的质量浓度(5、10和15 g/L)对MAO膜层微观结构和耐腐蚀性能的影响。结果表明:随着硅酸钠质量浓度的增大,微弧氧化过程中击穿电压降低,终止电压升高,MAO膜层表面微孔先减少后增多,总膜厚及致密层厚度先增大后减小,耐蚀性先增强后减弱。当硅酸钠质量浓度为10 g/L时,MAO膜层厚度为23.14μm,在3.5%NaCl溶液中极化电阻最大,腐蚀速率最低,耐腐蚀性能最佳。A ceramic film was prepared on the surface of ME21 magnesium alloy containing manganese and rare earth by micro-arc oxidation(MAO)technology.The effect of the mass concentration(5,10,or 15 g/L)of sodium silicate in electrolyte on microstructure and corrosion resistance of MAO film was studied by using scanning electron microscope(SEM),energy-dispersive spectrometer(EDS),X-ray diffractometer(XRD),and electrochemical workstation.The results showed that with the increasing of the mass concentration of sodium silicate,the breakdown voltage was decreased,while the termination voltage was increased during the micro-arc oxidation process,the number of micropores on the surface of MAO film was decreased initially and then increased,the thickness of the whole MAO film and the dense layer inside was increased initially and then decreased,and the corrosion resistance of MAO film was improved initially and then got worse.The MAO film prepared with 10 g/L of sodium silicate was 23.14-μm thick and had a largest polarization resistance in 3.5%NaCl solution,showing the lowest corrosion rate and the best corrosion resistance.

关 键 词：镁-锰-铈合金 微弧氧化 硅酸钠 微观结构 耐蚀性 

分 类 号：TG174.451[金属学及工艺—金属表面处理]