Chapter 52. Characterization of Spontaneously Formed Cerium–Based Conversion Coatings on Aluminum

  1. Hau-Tay Lin and
  2. Mrityunjay Singh
  1. W. G. Fahrenholtz1,
  2. Haifeng Zhou1 and
  3. M. J. O'Keefe2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294758.ch52

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4

How to Cite

Fahrenholtz, W. G., Zhou, H. and O'Keefe, M. J. (2002) Characterization of Spontaneously Formed Cerium–Based Conversion Coatings on Aluminum, in 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4 (eds H.-T. Lin and M. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294758.ch52

Author Information

  1. 1

    Department of Ceramic Engineering University of Missouri–Rolla Rolla, MO 65409

  2. 2

    Department of Metallurgical Engineering University of Missouri–Rolla Rolla, MO 65409

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375792

Online ISBN: 9780470294758

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Keywords:

  • aluminum alloys;
  • optimal coating;
  • coating morphology;
  • electron microscopy;
  • deoxidizing solution

Summary

Cerium oxide-based conversion coatings for aluminum alloys have been prepared by a spontaneous reaction between aluminum alloy test panels and a solution containing CeCl3. The effects of panel pre-treatment prior to coating, panel orientation in the coating solution, and coating time on coating morphology and performance were examined. Coating performance was evaluated by using ASTM B117 salt fog testing, and the optimal coating time was found to be between five and ten minutes. Coating morphology was characterized using scanning electron microscopy (SEM). Coatings that were deposited on the downward facing side of test panels pre-treated by desmutting, degreasing, and acid activation performed well in salt fog testing. Coatings that performed well in salt fog testing consisted of cerium-rich spherical nodules approximately 250 nm in diameter embedded in a featureless cerium-containing matrix.