Kinetic studies on the dissolution of the anodic oxide film on titanium in phosphoric acid solutions

摘要: Capacitance and potential measurements vs time show a two stage dissolution process in H3PO4 for the anodic oxide films formed galvanostatically on titanium. The mechanism of this duplex nature film follows zero order rate equation: thinning, −d(1/Cm)/dt is independent thickness, which corresponds to 1/Cm. at 15 V, has thickness larger than others, most stable solution highest electrochemical insulating properties. average constant entire K (cm2 μF−1 min−1), found increase with increasing acid concentration. effect anion type formation medium value also studied. In 0.1 N solutions different inorganic acids increases as increases, H2SO4 (low) < HCl HNO3 HCLO4 (high). results indicate that protective one lowest structural disorder.