Evaluations of Automotive Paints Coating Performance Using Electrochemical Impedance Spectroscopic Method


The aim of this paper is to study the corrosion rates and porosity of industrial paints used for car body coating. Seven types of industrial paints were used for car body structuresincluded 2K clear coat (Lacquers), Auto Paint 2K top coat, TS 16949 (Easi coat), Clear coat (Palinal), National Numix top coat, DENSO and ICI 2K solvent based (Tinters P420) were tested and studied using the electrochemical impedance spectroscopic (EIS) method. The liquefaction potable water solution was used as electrolyte for test. The obtained results showed that the Palinal paint has high impendence and lower porosity while TS 16949 (Easi coat) shows lower impedance and high porosity. Other types showed moderates values. Microscopic inspection of the surface coatings after EIS test showed that most paints had pitting corrosion except Auto paint shows blisters.