A New Tool for Corrosion Inhibitor Research

Electrochemical techniques such as repassivation potential measurements and electrochemical impedance spectroscopy (EIS) have become important tools in corrosion and corrosion inhibitor research. However, these techniques reflect the response of the total surface area of the exposed sample and cannot distinguish between types of localized corrosion e.g. pitting or crevice corrosion. Current density mapping (CDM) is a technique that uses a fine stainless steel needle, vibrating at a set frequency and scans over the surface of a sample in a plane micrometers above the sample surface. By mapping the current distribution over a surface, sites of localized corrosion can be characterized and the effect of a corrosion inhibitor monitored.