镁合金表面微弧氧化-溶胶凝胶复合膜层的结构及其耐蚀性

采用微弧氧化和溶胶凝胶技术在镁合金表面制备复合涂层,该涂层过渡层为微弧氧化膜层,外层为SiO2溶胶凝胶层。通过傅里叶红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)等分析技术对复合涂层成分、组织结构以及微观形貌进行了表征,并采用电化学测试方法综合分析了该复合涂层的耐蚀性能。研究表明,该复合涂层与基体结合较好,具有良好的高温稳定性,在质量分数为3.5%的NaCl溶液中腐蚀电位明显正移,腐蚀电流密度显著降低,表现出良好的耐蚀性。

Structure and Corrosion Resistance of Composite Coating Prepared by Micro-arc Oxidation and Sol-gel Methods on the Surface of Magnesium Alloy

Composite coatings were prepared on magnesium alloy by microarc oxidation (MAO) and sol-gel technique. The coatings consisted of a MAO transition layer and a solgel as outer layer. The composition, microstructure, morphology of coatings were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The corrosion properties of these coatings on magnesium alloy were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results show that the composite coatings have good properties, such as good binding with the substrates, and good stability at high temperatures. In 3.5% NaCl solution, its corrosion potential has a positive shift significantly, and the density of corrosion current is substantially reduced, showing a good corrosion resistance.