T. Yetim

Corrosion Behavior of Ag-doped TiO2 Coatings on Commercially Pure Titanium in Simulated Body Fluid Solution

TiO2 films including different amounts of Ag obtained by sol-gel method on commercially pure titanium (CP-Ti) and the corrosion properties of Ag-doped TiO2 films were investigated by potentiodynamic polarisation and Electrochemical Impedance Spectroscopy (EIS) tests in Simulated Body Fluid (SBF) solution. The results were compared with untreated and un-doped samples. Surface characterizations before and after the corrosion tests were performed by the Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. It was observed that Ag-doping for TiO2 films improved the corrosion resistance when compared with untreated and un-doped TiO2 film coated samples. The highest corrosion resistance was obtained from Ag-doped samples coated with a solution of 0.05 M Ag.

The Effects of Aging Time on the Structural and Electrochemical Properties of Composite Coatings on CP-Ti Substrate

TiO2-SiO2 composite films were produced on commercially pure titanium (CP-Ti) substrate by a sol–gel method to investigate the behavior of sol aging time and its potential effects on the structural and electrochemical properties of composite coatings. Anatase-TiO2 and quartz-SiO2 peaks were observed on all composite coated samples according to XRD results. It was observed that the average grain size increased with sol aging time. Also, the average smallest grain size was seen at composite coatings prepared from unaged sol according to the width of the peaks. Electrochemical behavior of coated samples was mainly investigated by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) in Simulated Body Fluid (SBF) solution. In corrosion tests, the composite coatings showed better anti-corrosion behavior than that of uncoated samples. In addition, the corrosion properties of the composite films were considerably affected by sol aging time. Corrosion resistance of coatings decreased with increasing aging time and the best result was obtained from composite coatings prepared from unaged sol.