Surface Coating Effect on Corrosion Resistance of Titanium Alloy Bone Implants by Anodizing Method

In the presented work, the formation of anodic oxide film on Ti-6Al-4V ELI (Extra Low Interstitial) alloy in 0.02 M trisodium phosphate (Na₃PO₄) electrolyte solution using various voltages were investigated. The color produced by the anodizing, the intensity of TiO2 content, the thickness of the oxide layer, and the corrosion rate were examined. It was obtained that the color appearance of Ti-6Al-4V ELI could be changed easily by altering the applied voltages. The higher the voltage applied in the anodizing process, the thicker the titanium oxide layer formed. The corrosion resistance analysis in a Simulated Body Fluid revealed that the non-anodized specimen showed a higher corrosion rate compared to the anodized specimen. The increase of oxide layer thickness leads to a significant decrease in corrosion rate and consequently increases the corrosion resistance. In addition, the anodized sample achieved the highest corrosion resistance at 15 V.