Electrochemical study of different ageing tests for the evaluation of a cataphoretic epoxy primer on aluminium

Different ageing tests (salt spray of intact and scratched samples, immersion) were used for the evaluation of the corrosion resistance of a lead-free epoxy primer used in the automotive industry and cataphoretically deposited on pre-treated aluminium 6016. The evaluation of the degree of degradation was carried out by electrochemical impedance spectroscopy. These tests were compared to accelerated degradation obtained by means of a test combining ac and dc polarizations.