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Hygroscopic Stress and Failure of Coating/Metal Systems.

pdf icon Hygroscopic Stress and Failure of Coating/Metal Systems. (721 K)
Perera, D. Y.; Nguyen, T.

Paint, Varnish, Ink and Adhesive Industry. Eurocoat Congress, 1996. September 1996, Italy, 1-17 pp, 1996.


coatings; stress; hygroscopic; corrosion; degradation; thermal analysis


Stress development in various types of organic coatings was determined under wet conditions. The values of hygroscopic stress obtained are correlated with the results of other tests such as electrochemical impedance spectroscopy, water uptake, adhesion, thermal analysis. The role of the hygroscopic stress in organic coating degradation is discussed. It is suggested that this stress participates in formation and/or enlargement of pathways in the coating, which enables the transport of the electrolyte to the metallic substrate provoking its corrosion. The knowledge of its destructive action will enhance our understanding of the controlling factors in corrosion of coated metals.