Effects of Acid and Alkaline Based Surface Preparations on Spray Deposited Cerium Based Conversion Coatings on Al 2024-T3
Cerium based conversion coatings were spray deposited on Al 2024-T3 and characterized to determine the effect of surface preparation on the deposition rate and surface morphology. It was found that activation of the panel using a 1-wt.% sulfuric acid solution increased the coating deposition rate compared to alkaline cleaning alone. Analysis of the surface morphology of the coatings showed that the coatings deposited on the acid treated panels exhibited fewer visible cracks compared to coatings on alkaline cleaned panels. Auger electron spectroscopy depth profiling showed that the acid activation decreased the thickness of the aluminum oxide layer and the concentration of magnesium on the surface of the panels compared to the alkaline treatment. Additionally, acid activation increased the copper concentration at the surface of the aluminum substrate. Based on the results, the acid based surface treatment appeared to expose copper rich intermetallics, thus increasing the number of cathodic sites on the surface, which led to an overall increase in the deposition rate.
W. R. Pinc et al., "Effects of Acid and Alkaline Based Surface Preparations on Spray Deposited Cerium Based Conversion Coatings on Al 2024-T3," Applied Surface Science, Elsevier, Jan 2009.
The definitive version is available at http://dx.doi.org/10.1016/j.apsusc.2008.10.110
Materials Science and Engineering
Strategic Environmental Research and Development Program (U.S.)
Keywords and Phrases
Aluminum 2024-T3; Cerium Conversion Coating; Coatings; Corrosion; Surface Preparation
Article - Journal
© 2009 Elsevier, All rights reserved.