Corrosion Behavior Of Ti And Anodic Oxidized TiO₂Film In Hydrothermal Region

In recent years, the scientists are very interested in the research of deep seahydrothermal region. Because of the activity of colcano and magna in the deep sea ofkilometers deep, the deep sea hydrothermal region that eruption is rich in sulphide.There are many mineral tip which are rich in copper、surphur、silver、gold element andother trace elements. The mineralize speed of these mineral tip is very fast, and theycan be used easily, So the exploitation of it looks promising. The life kind and densitycan be mentioned in the same breath of hylaea. All the world have reached aconsensus of the exploration and research about the deep sea hydrothermal region.While the equipment than can be working safely and efficiently is very important tous in the course of research and exploitation. Developing corrosion resistance of metalmaterial is the key to the equipment. Based on the excellent chemical properties ofTiO₂film, we want to produce TiO₂film on Ti and research its corrosion resistance，inorder to find and research a kind of material that can be used in deep sea hydrothermalarea.First, titanium oxide films were formed on metallic titanium substrates by anodicoxidation in the electrolyte of qlycerol and water at the ratio of9:1. By the result ofXRD spectrum、SEM and polarization curve, we make the voltage at20V,the time at2hour. The result of the angle of contact and EIS indicates that, as a kind ofsemiconductor, the hydrophobic property and corrosion resistance of TiO₂is better inthe dark which is very helpful for the application in deep sea hydrothermal region.Second, make a corrosion experiment by Ti sample and TiO₂sample at20℃and90℃, using the saturation solution of H2S with3.5%NaCl of mass fraction. We canfind from the result that the TiO₂sample can reduce the loss validly. The weight lossof the sample at90℃differs little, compared with the condition of20℃. By XRD spectrum, we can find TiH2were formed on Ti electrode, while the protection effect ofTiO₂, there is no TiH2on it. TiH2is harmful for the material.Third, make a corrosion experiment by Ti sample and TiO₂sample in deep seahydrothermal region simulation by hydrothermal synthesis reactor. Component,chemical composition，microstructure and hydrophobic properties were characterizedby X-ray diffraction（XRD）, Roman spectrometer, scanning electron microscopy（SEM）and water contact angle tester; electrochemical properties were researched throughpolarization curves. The result showed that in the simulative hydrothermal region，there is TiO₂film which cannot protect the matrix well, produced on Ti sample andanodic oxidation sample. The corrosion potential of Ti electrode removed towardsnegative direction of0.45V, and a mass of TiH2, was produced on it, while thecorrosion potential of sample by Anodic Oxidized changed less, and no TiH2wasproduced on it,because of the protection of anodic oxidation film.