EIS Study of the Electrochemical Behavior of the Co-Cr-Mo Alloy in Borate Solutions

• Main Authors: Montero-Ocampo, Cecilia, Hidalgo Badillo, Joaquín
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.2928908

This paper presents the results of EIS experiments performed to examine the passive state of Co-Cr-Mo alloy produced in borate buffer solutions of different pH values between 4.6 and 12.5 at rest potential. An equivalent circuit model was used for the quantification of the Co-Cr-Mo passive film properties obtained as function of solution pH. From this study, the solution pH which gives rise to the best passive protective properties was established to carry out the electropassivation of Co-Cr-Mo alloy at different potentials selected from the polarization curve. EIS experiments were implemented to evaluate the resultant passive state of Co-Cr-Mo alloy as function of the electropassivation potential. An equivalent circuit model used for measuring the Co-Cr-Mo passive film properties produced at these different electropassivation potentials shows that thicker and more resistant passive films were obtained using passivation potentials negative of the peak potential, 0.477 V presented in the anodic polarization curve.