Corrosion Behavior Of TiO₂ Film In Seawater

With the rapid development of science and technology, the relationships between humans and ocean were strengthened by the human activities including exploitations and researches of ocean resources. Metals especially the engineering material that was used in seawater suffered a severe corrosion in marine condition. Since the metal corrosion phenomenon is a big problem in marine environmental,urgent research works on developing corrosion resistant material is a task for academic institutions. Based on the excellent physical and chemical properties of TiO2 film, we want to make full use of the hydrophobic performance of TiO2 film in dark condition. The hydrophobic surface may isolate the direct contact between the surface and solution, reduce the ocean microbe attachment phenomenon and improve the material's corrosion resistance.First,titanium oxide films were formed on metallic titanium substrates by employing a thermal treatment under air atmosphere. Component of the oxide films were characterized by XRD technique.Contact angle tester and scanning electronic microscopy(SEM) methods were employed to investigate relationship between wetting propeties and microstructure of the oxide film,base on the wetting principles we have successfully improved the hydrophobic property of the oxide film .Second,sunlight effects on the wetting property of tatanium oxides film was also involved in our experiments. Natural seawater immersion experiments was employed in dark and sunlight irradiation condition. Through the electrochemical tests after immersion experiments we foud that: the hydrophilic TiO2 film suffered a photo-corrosion effect in seawater solution due to its semiconductor properties under sunlight; The hydrophobic TiO2 film exhibited a good corrosion resistance. Third,we have studied the microbe attachment state on TiO2 film surface. Results indicated that: the photo-reaction on TiO2 film under sunlight condition possesses the fuction to kill microbes at TiO2 film/seawater interface and the TiO2 film exhibited a favorable microbe attachment prevention property.