SiO₂和TiO₂及其复合改性耐蚀薄膜涂层的制备与性能

李明曦¹，江自然¹，刘恒¹，郑峰^{1, 2, 3}

(1. 中南大学 材料科学与工程学院，湖南 长沙，410083
2. 中南大学 粉末冶金国家重点实验室，湖南 长沙，410083
3. 中南大学 相图与材料设计及制备科学中心，湖南 长沙，410083)

摘 要：采用溶胶-凝胶法，以正硅酸乙酯(TEOS)、钛酸四丁酯(TBT)及γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)为前驱体原料，在45号钢片上制备SiO₂和TiO₂及其复合改性无机薄膜涂层。通过扫描电镜(SEM)观察其微观形貌、傅里叶红外光谱(FTIR)测试分析涂层所形成的化学键；通过盐浴实验和极化曲线测试改性涂层的防腐蚀性能。电化学测试结果表明：参照裸钢片，涂层试样的腐蚀电位提高了100 mV，其腐蚀速率下降了3个数量级。比较SiO₂和TiO₂及其复合结构薄膜涂层的耐腐蚀性能发现， SiO₂薄膜涂层的抗腐蚀性能最好。

关键词：有机改性；无机薄膜；防腐蚀；溶胶-凝胶；KH570

1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Science Center for Phase Diagram & Materials Design and Manufacture, Central So

LI Ming-xi¹, JIANG Zi-ran¹, LIU Heng¹, ZHENG Feng^{1, 2, 3}

(Corrosion resistance of SiO₂ and TiO₂ modified sol-gel coatings on mild steel surface)

Abstract:Using tetraethylorthosilicate (TEOS), tetrabutyltitanate (TBT) and γ-methacryloxypropyltrimeth-oxysilane (KH570) as precursors, SiO₂, TiO₂ and mixture of SiO₂-TiO₂ modified sol-gel coatings were prepared and applied to surfaces of No. 45 steel plate. Morphology or microstructure and binding of coatings were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) respectively. Anti-corrosion performance of the coating was examined by salt-bath testing and polarization measurements. Electrochemical results show that SiO₂-modified coating increases corrosion potential of the steel by more than 100 mV in 3.5%NaCl solution, which can be translated as nearly three orders of magnitude lower in corrosion rate compared with that of bare steel.

Key words:organic modified; inorganic coatings; anti-corrosion; sol-gel; KH570