Fast Current-Controlled Polarization for the Analysis of Rapid Cathodic Process on Anodized Metal

In the present work, a fast current-controlled polarization was proposed to examine a rapid cathodic process on anodized titanium substrates. Anodic oxide films with different thicknesses and structures were produced on titanium by anodization in a phosphate buffer solution at various voltages. In the fast current-controlled polarization, a triangle form of cathodic current with a maximum current density of 100 μA cm−2 was applied to the anodized titanium substrates in a buffer solution, and the resulting variation in potential was monitored. The potential for all the anodized substrates shifted sharply in less noble direction and then recovered back to the original value. The potential variations were analyzed, assuming that the applied current was consumed as charge-discharge current and oxygen reduction current. The oxygen reduction current behavior between the titanium substrates anodized at low voltages and those anodized at high voltages was different.