Bulk Ceramic Composites Derived from a Preceramic Polysilazane with Alumina and Zirconia Fillers

Authors

  • Thomas Konegger,

    Corresponding author
    1. Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-CT, 1060 Vienna, Austria
    • Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-CT, 1060 Vienna, Austria
    Search for more papers by this author
  • Antje Liersch,

    1. Department Materials Science, Glass and Ceramics, Koblenz University of Applied Sciences, Rheinstrasse 56, 56203 Hoehr-Grenzhausen, Germany
    Search for more papers by this author
  • Christian Gierl,

    1. Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164-CT, 1060 Vienna, Austria
    Search for more papers by this author
  • Michael Scheffler

    1. Institute for Materials and Joining Technology, Otto-von-Guericke University, Universitaetsplatz 2, 39106 Magdeburg, Germany
    Search for more papers by this author

  • The authors gratefully acknowledge Dr. Erich Halwax for assistance in XRD measurements, Karin Fussenegger for conduction of mercury intrusion porosimetry experiments, Jo Frank for assistance in green-body machining, as well as Prof. Noel Thomas for linguistic help with the manuscript.

Abstract

Bulk composites for the production of green-machinable, complex-shaped ceramic parts with tailorable properties for applications under mechanical stress are fabricated by a novel combination of a poly(vinyl)silazane-derived ceramic matrix with Al2O3 or ZrO2 fillers. Green-machinable composites were produced by coating of the filler powders with the preceramic polymer, followed by subsequent warm-pressing. The final ceramic materials are obtained by a thermal conversion process. A systematic variation of preceramic polymer content, pressure during warm-compaction, or pyrolytic conversion temperature is used to identify the main factors responsible for differences in densification behavior, microstructure, composition, and mechanical properties. The procedure of composite powder preparation as well as the optimization of the subsequent warm-pressing step are found to be decisive in the successful production of crack-free bulk ceramic composites.

Ancillary