Characterization of zinc-rich powder coatings by EIS and Raman spectroscopy
Language
en
Article de revue
This item was published in
Surface and Coatings Technology. 2002-08, vol. 157, n° 2-3, p. 151-161
Elsevier
English Abstract
In this work, the protective mechanisms of a single coat zinc-rich powder coating are examined. Powder coating panels were applied on phosphatized steel and were studied when immersed in artificial sea water with flowing ...Read more >
In this work, the protective mechanisms of a single coat zinc-rich powder coating are examined. Powder coating panels were applied on phosphatized steel and were studied when immersed in artificial sea water with flowing conditions. Open circuit potential and electrochemical impedance spectroscopy measurements were recorded to study changes in the coating properties with the exposure time. Moreover, Raman spectroscopy was used to analyze zinc corrosion products. This study reveals that the behavior of powder coating systems is different from solvent-based zinc-rich paints (ZRP). This is mainly attributed to the low porosity of powder coatings, due to their high wetting ability, which insulates some of the zinc particles. However, cathodic protection is active and provides the sealing of the coating pores. Finally, it is found that the barrier effect is higher than the one usually observed with solvent-based ZRP.Read less <
English Keywords
Zinc-rich paints; Powder coatings; Electrochemical impedance spectroscopy; Raman spectroscopy
Origin
Hal imported