Electrochemical Impedance Spectroscopy for Evaluation of Organic Coating Deterioration and under Film Corrosion -- A State of the Art Technical Review

摘要

This review evaluates and summarizes the technological developments and state of the art capabilities of the electrochemical impedance spectroscopy technique, as applied to the study of metallic corrosion under organic coatings. kinetic information was obtained on the rates of coating deterioration, metallic corrosion rates, percentage of area affected, and mechanisms for coating system degradation. Electrical equivalent circuit models which simulate the metal/coating/electrolyte interface aided in the analysis of the data obtained. Parameters relating to the degradation of the coating and subsequent corrosion of the substrate were measured simultaneously. Much greater quantitative information was provided than possible with conventional techniques such as visual inspections. The techniques used are nondestructive and have in-situ test capabilities. A summary of individual research articles published in the literature is included in the review. Some of the many EIS opportunities for Naval application are discussed, based upon an understanding of the conditions, techniques and work accomplished by others. Potential applications for EIS include evaluation of coating performance and corrosion rate as a function of coating formulation, surface preparation, coating defects, and alloy composition. The technique also has the potential for opportunity in the area of quality assurance.