The relations between chemical vapor deposition (CVD) parameters and the resultant pyrolytic carbon microstructures have been examined for matrix deposition in fibrous carbon substrates. The parameters considered are temperature (1200-145O"C), pressure (20-630 Torr), C/H ratio (l/4-1/14), total flow
Micromechanics of carbon fibers — chemical vapor deposited carbon composites
✍ Scribed by B.L. Butler
- Publisher
- Elsevier Science
- Year
- 1972
- Tongue
- English
- Weight
- 136 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0008-6223
No coin nor oath required. For personal study only.
✦ Synopsis
AASTRACTS 331 ment. The electron microscope (both in the scanning and transmission modes) was used to examine the topography of both wet (60% HNOs, 118°C) and dry oxidized (air, 700°C) fibers as well as fracture surfaces of composites made with treated and untreated fibers. The flexural strength of Type I reinforced epoxy composites increased with oxidation (wet) time, whereas for Type II reinforced composites, the strength decreased. The interlaminar shear strength of the former increased from 3000 to 10,000 psi, whereas only a slight improvement (-25 per cent) was observed for the latter. 25. Microporosity of carbon fibers L. Christner and P. L. Walker, Jr. (The Pennsylvania State University, University Park, Pennsylvanti f6802
). This paper will discuss the effect of carbonization temperature on the porosity of carbon fibers. Carbonization temperatures ranged from 220°C to 800°C. Porosity was determined by adsorption of carbon dioxide, butane and isobutane for various lengths of time with a maximum of 128 hr. Applicability of the molecular probe technique and activated adsorption will be considered.
📜 SIMILAR VOLUMES
## Abstrad-Tensile tests have been performed on carbon/carbon composites made from carbon cloths and a pyrolytic carbon matrix and their failure surfaces were examined by scanning electron microscopy. The load-extension curves are characterized by three distinct regions: the applied load needed to
Vapor-grown carbon-fiber (VGCF) reinforced carbon (VGCF-C) composites were studied for thermal and physical properties. Effect of fiber volume fraction and final density of composite on thermal conductivity was investigated. The fiber volume fractions range from 25 v/o to 36% and the final densitie
The work-of-fracture (ywOF) of carbon-carbon composites was measured for composites with 3-D woven fiber preforms, carbon felts, and chopped fibers. Maximum values were observed for the 3-D preforms and minimum values for the carbon felts. The values are also compared with similar data for graphites
Two-dimensional carbon/carbon composites were densified with carbon by pyrolysis of propane using the pulse chemical vapor infiltration (CVI) process which repeats the cycle of evacuation and introduction of gas. The experimental parameters were deposition temperature, reactant gas concentration, fl
An analysis of the reaction and diffusion of gases occurring simuitaneously with deposition of carbon in a porous material is presented. The model incorporates a scheme for the formation of carbon during the pyrolysis of a gaseous hydrocarbon to yield predictions for concentration and porosity profi