Surface characterization of oxides grown on the Ti–13Nb–13Zr alloy and their corrosion protection

• Oxide films were grown on the Ti–13Nb–13Zr alloy by three different procedures.
• Compact films were obtained at open-circuit potential and by potentiodynamic growth.
• Bilayered films were obtained only when micro-arc oxidation (MAO) at 300 V was used.
• The MAO oxide presents the best corrosion protection of the alloy in a PBS solution.

Oxide films were formed on the biocompatible alloy Ti–13Nb–13Zr in a phosphate buffer at open-circuit potential (Eoc), potentiodynamically up to 8 V, or by micro-arc oxidation (MAO) at 300 V. Their electrochemical properties were assessed in a phosphate buffer saline solution (PBS). EIS and SEM results showed that the Eoc and potentiodynamically formed oxide films were compact and behave as a monolayer, while the MAO oxide was a bilayered film (compact inner and porous outer layers). Open-circuit potential and EIS resistance values indicated that the MAO oxide provides the best corrosion protection for the alloy in PBS.