Film-Forming Mechanism Analysis of Cerium Conversion Coating on Zinc Coating

Abstract:

The zinc coating was immersed into a rare-earth conversion coating treatment liquid, with Ce(NO3)3•6H2O as the main salt and 30% H2O2 as the oxidizing agent. A Ce-H2O series potential-pH diagram and a Zn-H2O series potential-pH diagram were then established by calculating the maximum pH value obtainable on the interface. Therefore, the cerium conversion coating was deduced to be composed of ZnO, CeO2, Ce2O3, Ce(OH)3, and Ce(OH)4, In addition, XPS and XRD was used to analyze the appearance and phase of the cerium-based conversion coating in terms of the rare-earth conversion coating obtained in the experiment. The results reveal that the cerium-based conversion coating is the compound coating mainly consists of ZnO, CeO2, Ce2O3, Ce(OH)3 and Ce(OH)4, which is in line with the theoretical analysis.

• Periodical: Advanced Materials Research (Volumes 557-559)
• Pages: 1819-1824
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.557-559.1819
• Online since: July 2012
• Authors: Jiang Hong Zhang, Ying Jie Zhang
• Keywords: Cerium Conversion Coating, Film-Forming Mechanism, Zinc Coating

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