Thermal-shock behavior of a Nicalon-fiber-reinforced hybrid glass-ceramic composite

Nikhilesh Chawla, K. K. Chawla, M. Koopman, B. Patel, C. Coffin, J. I. Eldridge

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

A Nicalon-fiber-reinforced hybrid composite with a matrix of barium magnesium aluminosilicate (BMAS) glass with silicon carbide whiskers was subjected to thermal shock from elevated to ambient temperatures. The combination of SiC whisker and BMAS glass resulted in a hybrid matrix with a lower thermal expansion than that of the fibers, inducing tensile stresses in the fiber upon thermal shock. This stress state resulted in microstructural damage in the form of fiber cracking and cracking along the fiber/ matrix interface, as opposed to the conventional matrix cracking which is typically observed in ceramic-matrix composites. Significant damage in the composite was only observed after three thermal shock cycles. Flexural resonance measurements, used to evaluate thermal shock-induced changes in Young's modulus, showed a reduction in modulus that correlated well with the onset of microstructural damage. Finally, fiber push-out tests, performed to evaluate changes in fiber/matrix interface strength after thermal cycling, indicated a slight decrease in interfacial strength, which was attributed to recession of the carbon-rich fiber surface during thermal shock.

Original languageEnglish (US)
Pages (from-to)1923-1930
Number of pages8
JournalComposites Science and Technology
Volume61
Issue number13
DOIs
StatePublished - Oct 1 2001

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Keywords

  • A. Ceramic matrix composites
  • Damage
  • Fiber cracking
  • Thermal shock
  • Whisker

ASJC Scopus subject areas

  • Ceramics and Composites
  • Engineering(all)

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