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Article: Formation and characteristics of Al-Zn hydrotalcite coatings on galvanized steel.
- Article from:
- JCT Research
- Article date:
- October 1, 2004
- Author:
CopyrightCOPYRIGHT 2004 Federation of Societies for Coatings Technology. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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In this study, a process for depositing hydrotalcite (HT) coatings on galvanized steel was developed and the resulting coatings were characterized. Results showed that coatings formed spontaneously on galvanized surfaces upon exposure to ambient temperature alkaline aluminate solutions. Anodic polarization and electrochemical impedance spectroscopy experiments showed clear evidence of surface passivation. Scanning electron microscopy showed the formation of a continuous and conformal surface film comprised on a compact mass of crystallites. X-ray diffraction confirmed that the coating contained an Al-Zn hydrotalcite compound. Coating formation was enhanced by oxidizer and ...