STABILITY OF TITANIUM AND ITS PASSIVE FILMS IN ACIDIC AND NEUTRAL SOLUTIONS - EIS INVESTIGATION

Electrochemical impedance spectroscopy (EIS) technique has been used t o study the electrochemical behaviour and stability of thin oxide film s formed on titanium in different acidic and neutral solutions. The ef fect of formation voltage, formation current density and passivation m edium on the properties and stability of the anodic oxide films formed on titanium was also investigated. Titanium electrode showed high sta bility in perchloric acid and neutral salt solutions. The thickest ano dic oxide films have been obtained at a formation voltage of 8V. The s tability of the passive films are more affected by the passivation med ium than the dissolution one.