Microstructural and Strength Stability of CVD SiC Fibers in Argon Environment.
Abstract
The room temperature tensile strength and microstructure of three types of commercially available chemically vapor deposited silicon carbide fibers were measured after 1, 10, and 100 hr heat-treatments under argon pressures of 0.1 to 310 MPa at temperatures to 2100 deg C. Two types of fiber had carbon-rich surface coatings and the other contained no coating. All three fiber types showed strength degradation beyond 1400 deg C. Time and temperature of exposure had greater influence on strength degradation than argon pressure. Recrystallization and growth of near-stoichiometric SiC grains appears to be the dominant mechanism for the strength degradation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA240435
Entities
People
- David R. Hull
- Ramakrishna T. Bhatt
Organizations
- National Aeronautics and Space Administration