Influence of hydrogen peroxide on the corrosion of thermally oxidized ZrTi alloys in phosphate-buffered saline solution

The electrochemical behavior of Zr5Ti, Zr25Ti, and Zr45Ti alloys with surface modification was monitored in phosphate-buffered saline (PBS) solution, at the normal pH of the internal medium specific to healthy state (pH=7.3), and hydrogen peroxide added to PBS solution in order to simulate the inflammatory state, with a more acid medium (pH=4.9). A passive behavior for thermally oxidized ZrTi alloys was registered using linear potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Very low passive current densities were obtained from the anodic polarization curve, showing a passive behavior for all ZrTi alloys. The EIS data for all three alloy compositions were recorded for both pH solutions after 1 day, and 7 days immersion. From EIS data, an equivalent circuit (EC) for two time constants was modeled. The results showed that the Zr45Ti alloys with surface modification may be considered as potential candidates for biomedical applications based on their corrosion resistance in PBS solutions.