Effects of electrolyte ph on the electrochemical behavior of Fe-based bulk metallic glass

The effects of electrolyte pH on the electrochemical behavior of Fe-based bulk metallic glass with a composition of Fe 68.8 C 7.0 Si 3.5 B 5 P 9.6 Cr 2.1 Mo 2.0 Al 2.0 were investigated at an ambient temperature. The results indicate that corrosion behavior is strongly dependent on the pH values. The corrosion current densities and capacitance values decrease with an increase in pH values in acidic electrolytes, while the opposite tendencies are obtained in alkaline electrolytes. While the corrosion product of the outer layer in low pH conditions is an amorphous structure, crystalline ferric oxide is obtained in the electrolyte with pH=14. The electrochemical behavior is discussed on the basis of the results of electrochemical and microstructural analysis.