Chapter 5. Rheological Properties of Ceramic Formulations for Extrusion Freeform Fabrication

  1. Ersan Ustundag and
  2. Gary Fischman
  1. R. Vaidyanathan1,
  2. J. L. Lombardi1,
  3. B. Tennison1,
  4. S. Kasichainula2 and
  5. P. Calvert2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294567.ch5

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

How to Cite

Vaidyanathan, R., Lombardi, J. L., Tennison, B., Kasichainula, S. and Calvert, P. (1999) Rheological Properties of Ceramic Formulations for Extrusion Freeform Fabrication, in 23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3 (eds E. Ustundag and G. Fischman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294567.ch5

Author Information

  1. 1

    Advanced Ceramics Research, Inc. (ACR), Tucson, AZ 85706

  2. 2

    University of Arizona, Arizona Materials Laboratories, Tucson, AZ 85713

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1999

ISBN Information

Print ISBN: 9780470375631

Online ISBN: 9780470294567

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Keywords:

  • microstructures;
  • extrusion;
  • rheometry;
  • rheology 3-D components

Summary

A technology to fabricate complex, net shaped ceramic parts has been developed, based on extrusion freeform fabrication (EFF). The freeforming of ceramic parts was accomplished using a commercially available Stratasys 3D Modeler retrofitted with a high-pressure extrusion head designed by Advanced Ceramics Research, Inc. (ACR). The manufactured objects had good dimensional tolerances, as well as real engineering compositions and microstructures. The key to successful EFF is the use of a binder system that will give suitable Theological properties to the ceramic-binder system to ensure ease of being shaped into a green part by EFF. The green part is subsequently subjected to binder removal and sintering to produce fully dense structural ceramic components. The rheological properties of ceramic-loaded binder formulations developed by ACR and University of Arizona were evaluated using capillary rheometry and constant stress rheometry. The contribution of solids loading, binder composition, shear rate and temperature to the rheological properties were examined. The rheology of the ceramic-binder system was compared to that of similar ceramic-binder systems used for the Fused Deposition of Ceramics (FDC). The ceramic-binder formulations were found to be shear thinning in nature and highly non-Newtonian at the solids loading levels used. The formulation was non-ideal and strong particle-particle interactions were observed. The ceramic-binder system developed in this research is formable, has a very high volume fraction of powders, and found to perform well during binder-burnout and sintering.