INFLUENCE OF THE OPERATING VOLTAGE ON THE TITANIUM PASSIVATION PROCESS BY ANODIZING

Preliminary studies on Ti6Al4V titanium alloy samples were performed in order to investigate the influence of the operating conditions of the anodizing process on the corrosion resistance and chromatic effect of the oxidized surface. The voltage of the power supply varied in the range of 10 – 30 V, and the duration of the electrochemical deposition was about 80-90 seconds. The thickness of the anodized layer was calculated taking into account an average specific density of titanium oxide. Regarding the current density, it decreased continuously in the first 20 seconds, depending on the value of the supply voltage, then remaining constant until the end of the electrolysis. As a result of the experimental results, a directly proportional increase of the amount of deposited oxide and, implicitly, of the thickness of the samples was observed, together with the increase of the power supply voltage. The direct relationship between the supply voltage, the thickness of the deposited film and the colour of the titanium oxide layer obtained was also observed.