Electrochemical corrosion behavior and elasticity properties of Ti-6Al-xFe alloys for biomedical applications

As shown in Fig. 6, Ti-6Al-xFe alloys exhibit better corrosion resistance with lower anodic current densities, larger polarization resistances and higher open-circuit potentials in comparison with Ti-6Al and Ti-6Al-4V alloy. The addition of Fe can improve the corrosion resistance of Ti-6Al alloy due to the constitution of the protective oxide film formed on the surface. For titanium alloy, aluminum or iron oxidizes and forms a compact aluminum and iron oxide layer on the surface of passive film, which inhibits the dissolution of oxide film. As a result, the addition of Fe element in Ti-6Al alloy not only stabilizes the β phase, but also improves the stability of passive film for the improvement of corrosion resistance.