Enhanced corrosion resistance of Ti-6Al-7Nb and Ti-6Al-4V alloys through electrochemical surface treatment for biomedical applications

Electrochemical surface treatment (ET) was applied to Ti-6Al-7Nb and Ti-6Al-4V alloys to enhance their corrosion resistance for biomedical applications. Disk-shaped specimens were treated in a water-glycerin-lactic acid electrolyte under a constant voltage of 50 V. Corrosion behavior was evaluated by anodic polarization in 0.9% saline, and the surface chemistry was analyzed using X-ray photoelectron spectroscopy (XPS). ET shifted the corrosion potential toward more noble values and reduced the passive current density for both alloys. XPS revealed a marked increase in the Ti4+ fraction, indicating the formation of a TiO2-enriched surface layer. Overall, ET enhanced the passivation of high-strength titanium alloys used in medical and dental prostheses.