Effect of the anodization frequency and cathodic polarization on the corrosion resistance of CP titanium

The present work deals with recent progresses related to plasma electrolytic oxidation (PEO) performed in a pulsed bipolar regime, on titanium grade 2, in 0.5 M H2SO4, In particular, the effect of frequency and cathodic voltage (V-c) will be highlighted rationalizing the obtained results in terms of modification of the electrical double layer (EDL) formed at the oxide-electrolyte interface. Using low frequency (20 Hz) and relatively high V-c favour the development of thick (similar to 4.5 mu m) and compact oxides, ideals as a protection towards bromides rich environments. On the other hand, high frequency (1000 Hz) and a high V-c determine thick oxides (similar to 8 mu m) with lower compactness. This choice will be strategic for the production of oxides intended for use in acidic environments containing sulphates. Samples will be characterized for morphology (SEM) and the electrochemical behaviour investigated by potentiodynamic tests and electrochemical impedance spectroscopy (EIS).