Chapter 44. Processing and Performance of CFCCs Using Vacuum Assisted Resin Transfer Molding and Blackglas™ Preceramic Polymer Pyrolysis

  1. J. P. Singh
  1. M. N. Ghaseminejhad1,
  2. Jocelyn K. Bayliss1,
  3. R. Leung2 and
  4. J. G. Sikonia2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294437.ch44

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3

How to Cite

Ghaseminejhad, M. N., Bayliss, J. K., Leung, R. and Sikonia, J. G. (1997) Processing and Performance of CFCCs Using Vacuum Assisted Resin Transfer Molding and Blackglas™ Preceramic Polymer Pyrolysis, in Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3 (ed J. P. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294437.ch44

Author Information

  1. 1

    Advanced Materials Manufacturing Laboratory Department of Mechanical Engineering University of Hawaii at Manoa Honolulu, HI 96822

  2. 2

    Allied-Signal, Inc. Advanced Microelectronic Materials Santa Clara, CA 95054

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1997

ISBN Information

Print ISBN: 9780470375495

Online ISBN: 9780470294437

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Keywords:

  • polymer pyrolysis;
  • transfer molding;
  • ceramic matrix composites;
  • injection pressure;
  • microscopy

Summary

Vacuum assisted resin transfer molding (VARTM) used in conjunction with preceramic polymer pyrolysis proposes to be a cost effective method to manufacture continuous fiber ceramic composites (CFCCs) of complex geometry. In preceramic polymer technology, a polymer is used as a starting material, i.e., precursor, and hence conventional polymer manufacturing techniques, like VARTM, can be used to fabricate tubes that upon reinfiltration/pyrolysis cycle yield ceramic matrix composites (CMCs). In this research, four CMC tubes were fabricated using this technique. Total VARTM manufacturing time averaged 15 minutes for each tube. The matrix material used was Blackglas™. Two different ceramic fibers were used as reinforcements: Carbon coated Nicalon™ in form of woven fabric, and boron nitride coated Nextel™ in form of braided textile. For each fiber/matrix combination, two VARTM techniques were used. One technique was to use injection pressure supplied by the RTM machine in the presence of a vacuum in the mold, and the other technique was the use of vacuum only without the injection pressure, where resin flows due to (a) gravity, (b) capillary effects, and (c) vacuum assistance. Eight to ten pyrolysis cycles were necessary to reach a convergence by weight. Nicalon™/Blackglas™ CFCC tubes of good quality with 2–6% porosity, 44–56% fiber volume fraction, and 2.26–2.30 g/cm3 reached convergence by weight in about ten days. Nextel™/Blackglas™ tubes of good quality with 4–5% porosity, 72–75% fiber volume fraction, and 2.28 − 2.32 g/cm3 converged by weight in eight days. The mechanical performance of the components was evaluated at room and high temperatures using a C-Ring test. Scanning Electron Microscopy (SEM) was employed to study the microstructure of the finished parts before and after mechanical testing. A comparison between parts manufactured by the two VARTM techniques, that is with and without injection pressure; shows that the without injection pressure technique offers a promising method to produce tubular CMCs in terms of lower manufacturing costs, part uniformity, and enhanced mechanical properties. Boron nitride coating performs better at high temperature compared with carbon-coating. Also, a combination of boron nitride coating and a textile braided architecture of fiber preform in the mold proved to enhance the performance of the manufactured CFCCs significantly.