Structure and protective properties of TiO2 coatings obtained using the sol-gel technique

The paper presents a method for obtaining TiO2 coatings from a liquid phase. The precursor tetaisopropyl orthotitanate Ti(C3H7O)4 was used. X-ray diffraction analysis indicated that the TiO2 coating obtained was the rutile type. Polarization experiments showed that the coating inhibits both cathodic and anodic processes, and the steel corrosion rate drops by 100 times, as compared to those of a bare steel surface. Electrochemical impedance spectroscopy measurements used for the assessment of corrosion protection of the coating indicated that the deposited TiO2 films have poor barrier properties, with coating defects causing considerable scatter in the results. The study was aimed at obtaining the titanium dioxide coating on chromium stainless steel surface to examine its corrosion protecting properties in solution of 0.5M Na2SO4 acidified down to pH 3. Materials used: AISI403 stainless steels.