Statistical evaluation of EIS and ENM data collected for monitoring corrosion barrier properties of organic coatings on Al-2024-T3

By Shin, J.H.; Kim, K.W.; Ahn, H.J. & Ahn, J.H.
Published in Corrosion Science NULL 2002

Abstract

This paper describes the statistical treatment of electrochemical noise (electrochemical noise methods, ENM) and impedance (electrochemical impedance spectroscopy, EIS) data collected for corrosion monitoring of epoxy coated aluminum 2024-T3. The epoxy was applied using electrodeposition to Al-2024-T3 panels treated with one of three surface pretreatments. Six coating systems were prepared by varying the electrodeposition parameters and the pretreatment. Linear regression analysis of the data was used to detect the individual contributions relating to the analysis technique, topcoat application and pretreatment type. As a result of the statistical treatment it was found that EIS data has significantly less variance compared to ENM data, that EIS data can be used to differentiate the effects generated from the coating and pretreatment, and that ENM data cannot be used to differentiate the effects generated from the coating and pretreatment due to the high variance in data values associated with ENM. None of this information could be quantified without the statistical treatment.

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