Corrosion Behavior Of Anodic Oxidation Titanium Dioxide Film In Seawater

With the development of productivity and modern technology, the relationship between human and ocean were reinforced by the human exploitations and research activities. Meanwhile, thousands of metal materials with different type and properties were used in the marine scientific research and oceanic engineering. However, these metal materials may be corroded by seawater solution and the special marine environment, 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 preparation condotions, also with some excellent corrosion resistant polymer materials in the oceanic environment. The TiO2 film may inhibit a direct contact between the metal and solution, high polymers also can change the surface hydrophobicity, reducing sloution penetration, increasing material's corrosion resistance.First, TiO2 films were formed on metallic titanium substrates by anodic oxidation method in H2SO4 solution. Component, microstructure and hydrophobic properties were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and water contact angle tester; electrochemical properties were researched through electrochemistry impedance spectrum(EIS) and polarization curves. The result showed that the TiO2 film prepared by anodic oxidation method owned better corrosion resistance, and its hydrophobic property in dark condition increase corrosion resistance in seawater solution.Second, PANI/TiO2 compostie films were prepared on metallic titanium substrates by potentiostatic method in H2SO4/An solution. Microstructure and hydrophobic properties were characterized by scanning electron microscopy (SEM) and water contact angle tester; electrochemical properties were researched through electrochemistry impedance spectrum (EIS) and polarization curves. The result showed that the PANI/TiO2 compostie film prepared by potentiostatic method owned better hydrophobic property and corrosion resistance in alkalescent seawater, and it decreased the metal corrosion rate greatly.Third, in order to increase the surface hydrophobicity, polystyrene sphere was used in this part. Using chemical and physical methods to cover a thin hydrophobic surface on TiO2 which prepared by anodic oxidation method. Water contact angle method and electrochemical method were used to test their hydrophobic properties and corrosion performances. The result showed that oxidation film modified by hydrophobic materials can isolate seawater penetrate into the surface effectively, hence reduce corrosion effects seawater caused.