Effect of Nb addition on the stability and biological corrosion resistance of Ti-Zr alloy passivation films

The effect of Nb addition on the biological corrosion behavior and passivation film characteristics of Ti-Zr alloys in simulated body fluid solution has been systematically investigated. Potentiodynamic polarization analysis, Mott-Schottky analysis, and electrochemical impedance spectroscopy analysis revealed that, with increasing Nb content, the corrosion resistance of alloys first decreases and then starts to increase when the amount of Nb added is 20 at%. The addition of Nb can stabilize the passivation film of Ti-Zr alloys and reduce pitting sensitivity. The mechanisms of the effect of Nb on the corrosion resistance and stability of the passivation film have been extensively discussed.