EIS and ENM measurements for three different organic coatings on aluminum

Electrochemical impedance spectroscopy (EIS) and Electrochemical noise measurements (ENM) were used to evaluate protective properties of three different organic coating systems. The coatings under investigation were two-component aerospace coatings, applied on aluminum substrate. They were immersed in a 0.5 mol l(-1) sodium chloride (NaCl) solution, within a controlled flow cell and were tested for 1 year. The impedance modulus in the low frequency domain and the noise resistance were calculated and compared. From EIS data, coating capacitances and coating resistances of coating performance were estimated. The electrochemical results are in good agreement with final visual observations. The results of this study yield a performance ranking of the three different coatings. (C) 2001 Elsevier Science B.V. Ail rights reserved.