95. Manufacturing of Thick Layers Made from Nanosized SiO2 Powders by dip-Coating

  1. Edgar Lara-Curzio and
  2. Michael J. Readey
  1. Georg Fehringer and
  2. Rolf Clasen

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291191.ch95

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

How to Cite

Fehringer, G. and Clasen, R. (2004) Manufacturing of Thick Layers Made from Nanosized SiO2 Powders by dip-Coating, in 28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4 (eds E. Lara-Curzio and M. J. Readey), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291191.ch95

Author Information

  1. Saarland University, Department of Powder Technology Geb. 43, D-66123 Saarbrucken, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2004

ISBN Information

Print ISBN: 9780470051528

Online ISBN: 9780470291191

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Keywords:

  • bioceramic system;
  • hydroxylapatite;
  • rietveld method;
  • x-ray powder diffraction;
  • polycrystalline materials

Summary

The sol-gel process is one of the most commonly used techniques realizing thin coatings by dip-coating on different substrates, such as glass. However the thickness of the layers is limited to a few hundred nanometers. For making layers thicker than 1 urn there are other techniques like dip-coating with aqueous suspensions. Such layers can improve the wear and chemical resistance of glasses.

The Manufacturing of thick SiO2-layers with a thickness of more than 4 fim (green stage) can be made by dip-coating with aqueous suspensions on borosilicate glass. These suspensions are made of nanosized fumed silica (DEGUSSA, Aerosil OX50). By adding methylcellulosis (MC, Sigma-Aldrich) as binder it is possible to increase the maximum layer thickness to about 7 μm.

The layers were sintered with a CO2 laser. Applying this gradient method it is possible to sinter high-temperature materials on thermally sensitive substrates. The thickness of layers made by suspension consisting a binder, were about 3 μm after sintering.

The green and sintered layers were characterized by profilometry, scratch-test and HR-SEM.