High-Temperature Creep of Carbon Yarns and Composites.
Abstract
Effects of creep and deformation at high temperatures in carbon-carbon composites have been investigated. High-temperature creep in composites may play an important role in processing, through relaxation of thermally induced stresses caused by thermal expansion anisotropy of graphite. Creep has been measured in unidirectional composites at temperatures between 2000 and 3000 C. Various distinctions have been observed among the creep behaviors of composites utilizing PAN-, rayon-, and mesophase-pitch-based carbon fibers, such as decreasing creep rates and elongations with increasing stiffness and degree of graphitic disorder. Fiber-matrix debonding at high temperature, such as that in microstructural observations using SEM, occurs after high-temperature deformation and is visible in the interior of microcracks and at fracture ends. Estimates of relative thermal expansion coefficients of different fiber composites under low stress in the creep regime have been obtained. (MM)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1987
- Accession Number
- ADA302277
Entities
People
- L. A. Feldman
Organizations
- The Aerospace Corporation