低碳钢纳米TiO2涂层的结构、形貌与防腐性能

Structure,Morphology and Corrosion Resistance of Nano-Sized Titanium Dioxide Coating on Low Carbon Steel Surface

采用溶胶-凝胶法与浸渍提拉技术在经碱性发黑和热处理后的低碳钢上制备纳米TiO2涂层.通过扫描电子显微镜(SEM)、X射线衍射(XRD)及X射线光电子能谱(XPS)对涂层的结构、形貌及组成进行表征,采用电化学方法研究涂层的防腐蚀性能.结果表明:所制备的纳米TiO2涂层外观呈蓝灰色,表面存在大小不等的微裂纹;XRD分析表明纳米TiO2为锐钛矿型;XPS分析表明涂层主要由Ti、Fe、O和C 4种元素组成;稳定电位和Tafel曲线测试表明纳米TiO2涂层对于低碳钢具有一定的防腐蚀性能,在2.5%NaHCO3溶液中光电化学效应明显,在3%NaC l溶液中光电化学效应不明显.

Nano-sized titanium dioxide coatings were prepared on low carbon steel after alkaline blackening and heat treatment via the sol-gel method. The structure, morphology and composition of the prepared coatings were then characterized by means of SEM, XRD and XPS, and the corrosion resistance of the coatings was investigated via the electrochemical method. SEM results indicate that the coatings look blue-grey with many small size-variable cracks and fractures on the surface, XRD spectra show that the coatings are of the anatase structure, and XPS resuits indicate that the coatings are mainly composed of Ti, Fe, O and C. Moreover, the tested results of stable potential and Tafel curves demonstrate that the nano-sized TiO2 coatings, which protect the low carbon steel from corrosion, are of better photo-electrochemical properties in 2.5% NaHCO3 solution than in 3% NaCl solution.