Effect of Experimental Parameters on Passivation Phenomena of Ti6AI4V Alloy in Acid Solution

摘要

This paper study the effect of scan rates and imposed potential on the growth of the oxide film on the Ti6Al4V alloy surface in acid solution .Polarization curves, plotted at different scan rates show a large range of passivation, with no occurrence of transpassivation . It was found that the scan rate have not a significant effect on the passivation phenomenon. However, it influences the corrosion potential and the current density. Electrochemical impedance spectroscopy results show that the system behaviour is purely capacitive. The increasing trend in transfer resistance, film thickness and the exponent n with the imposed potential is due to the growth of a passive and compact oxide film.