不锈钢表面纳米SnO2/TiO2复合薄膜制备及防腐蚀性能

采用溶胶凝胶法在不锈钢基体(304ss)上制备叠层式纳米SnO2/TiO2复合薄膜。使用X射线衍射(XRD)、扫描电子显微镜(SEM)表征纳米复合薄膜材料的晶体结构和微观形貌,通过交流阻抗技术(EIS)和极化曲线(Polarization Curves)电化学方法研究不锈钢表面纳米复合薄膜在模拟海水体系中的腐蚀行为。结果表明:制备叠层式纳米复合薄膜TiO2为锐钛矿型,SnO2为金红石型;不锈钢表面构筑叠层式纳米SnO2/TiO2复合薄膜颗粒粒径小,分布均匀且表面致密。电化学测试表明,叠层式纳米SnO2/TiO2复合薄膜阻抗值高于TiO2薄膜,且对不锈钢基体阳极反应有明显钝化过程,具有良好防腐蚀性能;同时叠层式纳米SnO2/TiO2复合薄膜存在最优叠加SnO2层数,叠加3层SnO2的纳米SnO2/TiO2复合薄膜电极防腐蚀性能最佳。

Preparation of Nano-SnO2/TiO2 Composite Thin Films on 304 Stainless Steel and Its Anticorrosion Performance

The layer-stacked TiO2/SnO2 nano sized composite thin films were successfully prepared by sol-gel method and deposited on 304ss subtracts.The structure and the surface morphology of the composite thin films were characterized physically by X-ray diffraction(XRD)and scanning electron microscope(SEM).The anticorrosion properties of the composite films in simulate seawater have been studied by Polarization Curves and EIS.The result showed TiO2 is anatase phase and SnO2 is rutile phase at 450℃ heat treatment;SEM results indicated that layer-stacked SnO2/TiO2 nano sized film with small particle size,uniform distribution and compact surface is constructed on the surface of stainless steel;the electrochemical tests showed that the impedance value of the composite SnO2/TiO2 film is higher than that of TiO2 film,and it has obvious passivation process on the anode reaction of stainless steel.At the same time,there is the best stack layer number of SnO2.By the contrast,the composite films with three-layer SnO2 loading had the highest anticorrosion efficiency.