Hygroscopic Stress and Failure of Coating/Metal Systems.
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.
Keywords:
coatings; stress; hygroscopic; corrosion; degradation;
thermal analysis
Abstract:
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.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899