Sol-gel法镁合金表面制备SiO_2涂层及其腐蚀性能研究

Preparation of SiO_2 Coating on Mg Alloy Surface by Sol-gel Process and Its Corrosion Resistance

利用有机醇盐水解法制备了SiO2溶胶,采用溶胶-凝胶法在AZ91D镁合金表面制备了SiO2涂层。通过SEM、XRD等分析技术对涂层表面结构和组织进行表征,并探讨了该涂层的耐腐蚀性能及涂覆次数对腐蚀性能的影响。结果表明:以正硅酸乙酯为原料、无水乙醇为溶剂、盐酸为催化剂,可制备出均匀透明的SiO2溶胶;3.5%NaCl水溶液浸泡腐蚀试验表明,SiO2涂层显著提高了镁合金表面的耐腐蚀性能。

SiO2 coating on the surface of AZ91D alloy was prepared using sol-gel method. The surface structure and microstructure of the coatings were described through SEM, XRD and other analytical techniques. The results show that a uniform, transparent SiO2 sol can be prepared using TEOS as raw materials, ethanol as solvent, hydrochloric acid as catalyst. The results of the test of 3.5% NaCl aqueous solution immersion show that the corrosion resistance of the substrate is greatly improved by SiO2 coating.