Electrochemical Behavior and Characterization of Passive Film Formed on Plasma-Sprayed Fe-Cr-Mo-C-B Metallic Glass Coating

In this study, an Fe-Cr-Mo-C-B (FeCrMoCB) metallic glass coating was prepared by atmospheric plasma spraying. The composition and morphology of the as-sprayed FeCrMoCB metallic glass coating were characterized by x-ray diffraction and scanning electron microscopy. A potentiostatic polarization study was performed for different times to evaluate the changes in the growth process of the passive film. The impedance value of the passive film and the passivation time were found to be in good agreement with the logarithmic relationship within 24 h of passivation. After 24 h of potentiostatic polarization, the impedance value of the passive film was significantly improved to 1.54 ×  × 105 Ω⋅cm2 and the carrier concentration was increased to 1.10 × 1021 cm−3. The results of x-ray photoelectron spectroscopy analysis showed that the increase in oxide content, especially Cr2O3, and the decrease in hydroxide content in the passive film may be the main reason for the improved corrosion resistance of the passive film.