SiO_2-TiO_2-ZrO_2溶胶低温固化涂层的组织结构及耐盐雾腐蚀性能

SiO2-TiO2-ZrO2溶胶高温固化制备的涂层无光泽。以正硅酸乙酯(TEOS)、钛酸丁酯(TBT)和氧氯化锆(ZrOCl2.8H2O)等为原料制备SiO2-TiO2-ZrO2溶胶,研究了其不同温度固化后的粉末的分子结构、物相及热性能,并分析了溶胶低温(100℃)固化处理所得涂层的表面形貌、透过率及耐盐雾腐蚀性。结果表明:100～800℃固化,TEOS与TBT水解完全,经缩合反应形成Ti-O-Si键,Zr4+可能存在于Ti-O-Si的网络结构间隙中;低温(100℃)固化所得干凝胶为非晶态,热稳定性好;低温(100℃)固化制得的涂层无色透明、有光泽,可保持基底原色,表面均匀、无开裂,能对基材起到良好的防腐蚀作用。

Microstructure and Corrosion Resistance of Coating Obtained by Curing of Silica-Titania-Zirconia Sol at Low Temperature

Tetraethylorthosilicate(TEOS),tetrabutyl titanate(TBT) and ZrOCl 2.8H 2 O were employed as the starting materials to prepare SiO2-TiO2-ZrO2 sol.The molecular structure,phase composition and thermal stability of the powder obtained from the sol cured at different temperature were analyzed.More over,as-obtained SiO2-TiO2-ZrO2 sol was cured at relatively lower temperature of 100 ℃ to form coating,and the morphology,transmissivity and corrosion resistance against salt-spray of the coating were examined.It was found that,when cured at 100～800 ℃,TEOS and TBT were completely hydrolyzed to form Ti-O-Si bond via condensation,while Zr 4 + seemed to be located at the interspace of the Ti-O-Si networks.The dried sol obtained at low curing temperature(100 ℃) was amorphous and had good thermal stability.The coating obtained at low curing temperature(100 ℃) was colorless,transparent and lustrous,and retained the color of the substrate.Besides,the surface of the coating was uniform and free of cracking,and the coating could well prevent the stainless steel substrate from corrosion.