Corrosion behaviors of a new titanium alloy TZNT for surgical implant application in Ringer's solution

A new near α-titanium alloy Ti12.5Zr2.5Nb2.5Ta (TZNT) for surgical implants was designed. The potentiodynamic technique was performed to investigate the corrosion behaviors of TZNT in Ringer's solution, and Ti6Al4V, Ti6Al7Nb, and TA2 were taken as comparison. The structure of the passive film was analyzed using an X-ray photoelectron spectrometer (XPS). The results indicate that TZNT possesses better corrosion resistance, when compared with Ti6Al4V, Ti6Al7Nb, and TA2. The passive film formed on the TZNT surface is composed of oxides, such as TiO₂, ZrO₂, Nb ₂O₅, and Ta₂O₅. The elements Zr and Ta are rich, whereas Ti and Nb are poor in the passive film. The addition of Zr, Nb, and Ta with relatively low electrochemical reaction potentials can reduce the anode activity and improve passive properties. Other than that, oxides such as ZrO₂, Nb₂O₅, and Ta₂O₅ with the nobler equilibrium constants make the passive film more stable.