Strength Degrading Mechanisms for CVD SCS-6 SiC Fibers in Argon Environments.

Abstract

The room temperature tensile strengths of chemically vapor deposited SCS-6 silicon carbide fibers were measured after 1 to 400 hr heat-treatments in 0.1 MPa argon at temperatures to 2100 deg C. The fibers heat treated for 1 hr above 1400 deg C and those heat treated for 400 hr above 1300 deg C showed strength degradation. Scanning and transmission electron microscopic examination of the degraded fibers showed formation of a recrystallization region within the outer zone of the SiC sheath and the growth of SiC particles in the carbon-rich surface coating. The activation energies for the growth of the recrystallization region and the SiC particles were approx. 370 KJ/mole and approx. 320 KJ/mole, respectively. Strength of the fibers was found to vary as an inverse function of the recrystallized zone thickness.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1996
Accession Number
ADA309358

Entities

People

  • David R. Hull
  • Ramakrishna T. Bhatt

Organizations

  • Glenn Research Center

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Ceramic Matrix Composites
  • Chemical Vapor Deposition
  • Composite Material Fabrication
  • Composite Materials
  • Crystal Structure
  • Degradation
  • Electron Microscopes
  • Electron Microscopy
  • Energy
  • Grain Boundaries
  • Grain Growth
  • Heat Energy
  • Heat Of Activation
  • Heat Treatment
  • Materials
  • Silicon Carbide
  • X Rays

Fields of Study

  • Materials science

Readers

  • Metallurgy
  • Optical Fiber Sensing and Electromagnetic Propagation.
  • Thin Film Deposition Science.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene