The effect of anodizing conditions on the corrosion resistance of Ti6Al4V titanium alloy

To improve the biocompatibility and operational safety of titanium implants made of Ti6Al4V alloy, anodizing is applied. The anodizing process allows adjustment of the highly biocompatible oxide level on the metallic surface. However, little attention is paid to the influence of the layer thickness on the considered material corrosion resistance. Electrochemical polarization and open circuit potential tests as well as scanning electron microscope, laser confocal microscope and energy-dispersive X-ray studies were performed on as-received samples. Taking all experimental investigations into account, the following conclusions can be formulated: 1. Anodizing of Ti6Al4V alloy results in improvement of its corrosive characteristics. 2. In general, the higher the anodizing voltage is, the worse the anticorrosive properties exhibited by the material. 3. Despite the observed corrosion characteristics, the titanium oxide films obtained by means of the anodizing technique can be severely corroded in 0.9 wt.-% NaCl aqueous solution.