Thermal conductivity of oriented fibrous carbon insulation from 300 to 1300 K in nitrogen and argon at one atmosphere
From joint meeting of the American Nuclear Society and the Atomic Industrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). The thermal conductivity, lambda , of three samples of oriented fibrous carbon insulation was measured from 300 to 1300 deg K in a radial heat- flow apparatus. Preparation of the 0.18 g/cm/sup 3/-density samples by a vacuum filtration process from carbon fibers and powdered phenolic resin, characterization of the material after carbonization, and typical mechanical properties are described. The lambda of these low-density composites depended on both the heat-treatment temperature and the fiber orientation. For samples heat treated at 1575 deg K, the room-temperature lambda perpendicular to the planes of fibers was about 0.5 mW cm/sup -1/K/sup -1/ and was three times as high in the direction parallel to the planes. At 1000 deg K, the lambda in both directions had doubled, primarily because of the positive d lambda /dT of the amorphous carbon fibers. Material heat treated at 2775 deg K had a significantly higher room-temperature lambda and a negative d lambda /dT, indicating that a slight degree of ordering or graphitization had occurred in the fibers during heat treatment. At high temperatures, lambda of all three samples increased markedly because of radiative heat transport. (auth)
- Research Organization:
- Oak Ridge National Lab., Tenn. (USA)
- NSA Number:
- NSA-29-008366
- OSTI ID:
- 4380608
- Report Number(s):
- CONF-731101--33
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
*THERMAL INSULATION-- THERMAL CONDUCTIVITY
*THERMONUCLEAR REACTORS-- THERMAL INSULATION
CARBONIZATION
DENSITY
FILAMENTS
HIGH TEMPERATURE
MECHANICAL PROPERTIES
MEDIUM TEMPERATURE
N50330* --Metals
Ceramics
& Other Materials--Plastics & Other Materials--Properties
Structure & Phase Studies
N70800 --Physics--Controlled Thermonuclear Research--Thermonuclear Engineering & Equipment
ORDER PARAMETERS
ORIENTATION
POWDERS
RADIANT HEAT TRANSFER
RESINS
SAMPLE PREPARATION
VERY HIGH TEMPERATURE