Correlation between electrochemical noise measurements and physico-mechanical testing of ZRP loaded with Al particles

摘要

The modified approach is proposed to establish correspondence between electrochemical noise (EN) measurements in zinc rich paints (ZRP) loaded with AI particles and physico-mechanical testing performed for different types of mentioned coatings. Physico-mechanical tests were employed to confirm that low frequency noise impedance spectrum modulus of impedance (Z_(0.08Hz)) value and noise resistance R_n value (both changing with immersion time of tested coatings in 0.05 M NaCI solution) are both in relation to physico-mechanical tests results. Results of physico-mechanical tests suggest that structural inhomogeneity (different for different types of tested coatings) can be the main cause of formation of structural defects in tested coatings during immersion in 0.05 M NaCI solution. After 168 hrs exposure of tested coatings thus Z_(0.08Hz) value will be most heavily influenced by barrier properties of coating, while R_n value will be strongly influenced by the presence of imperfections and the holes in the coating due to methods of preparation of coating.