Electrochemical behaviors and passive film properties of Fe-based bulk metallic glass in Cl?-containing acetic acid solutions under high temperature
By Liang, D. D.; Wei, X. S.; Wang, Y.; Jiang, H. R.; Shen, J.
Published in Journal of Alloys and Compounds
2018
Abstract
This study aimed to investigate the electrochemical behavior and passive film properties of Fe-based bulk metallic glass (BMG) formed in Cl?-containing acetic acid solutions under high temperature. Electrochemical tests showed that Fe-based BMG exhibited excellent pitting resistance and stable passivation characteristics. However, the uniform corrosion resistance of Fe-based BMG is deteriorated in the presence of Cl? anions. Mott-Schottky, X-ray photoelectron spectroscopy depth profiling, and ultra-violet photoelectron spectroscopy analyses revealed that the passive films possess a duplex membrane structure. High-valence cations and Cl? anions relatively localized in the external layer, whereas low-valence cations relatively localized in the internal layer. Moreover, Cl? exposure increases the porosity and decreases the compactness of the passive film by modifying stoichiometry, improving acceptor density, reducing work function, and enhancing the state density of valence electrons around the Fermi level. Results implied that Fe-based BMGs are potential substitutes for conventional stainless steel components that are exposed to organic manufacturing environments.