Evolution and corrosion resistance of passive film with polarization potential on Ti-5Al-5Mo-5V-1Fe-1Cr alloy in simulated marine environments

Evolution and corrosion resistance of passive film with anodic polarization potentials on Ti-5Al-5Mo-5 V-1Fe-1Cr alloy in a 3.5 wt% NaCl solution were investigated. The valence state of Ti element increased, while the passive film corrosion resistance exhibited an evolution trend from weak to strong and then to weak with increasing polarization potential. Adsorption energy calculations of Cl^- indicated a stable adsorption of Cl^- on the TiO₂. Combined with the corrosion effect of corrosive ions on metal hydroxides, the passive film compactness would decrease and the roughness would increase, triggering a decrease in the passive film corrosion resistance as potential increased.