机构地区: 中国科学院海洋研究所
出 处: 《中国腐蚀与防护学报》 2005年第6期332-335,共4页
摘 要: 采用不同的氧化电流密度(20 mA/cm2、50 mA/cm27、0 mA/cm21、00 mA/cm2),在碱性硅酸盐溶液中镁合金AZ91D表面制得了一系列的微弧氧化膜,并且利用体视显微镜方法、X射线衍射方法和电化学阻抗方法对膜层的表面形貌、结构组成以及电化学阻抗等性能进行了比较研究.结果表明,氧化电流密度越高,膜层的生长速度越快,膜层的晶化程度越高,但是膜层的粗糙度和孔隙率升高,阻抗反而下降。膜层的阻抗性能不是由膜层的总厚度决定,而是主要取决于氧化膜的致密程度. By using optical microscopy, X- ray diffraction(XRD) and electrochemical impedance spectroscopy (EIS) technique, the structure, composition characteristics and the electrochemical properties of micro- arc oxidation(MAO) coatings prepared at different current density on AZ91D magnesium alloy were studied. It was found that with increasing the current density, the growth rate of the coating and its crystallization became higher, while the roughness and porosity of the coatings increased, and the film resistance Rf decreased. The properties of the coating were not determined by the total thickness, but the structure of the coating.