NASA Reference Publication, Issue 1254National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1977 - Astronautics |
From inside the book
Results 1-5 of 34
Page 15
... Exhibit , Soc . of Aerospace Material and Pro- cess Engineers , 1968 , Paper II - 4B - 2 . Defense 12. Kotlensky , W. V .; and Pappis , J .: Mechanical Properties of CVD Infiltrated Composites . Proceedings of 9th Biennial Conference on ...
... Exhibit , Soc . of Aerospace Material and Pro- cess Engineers , 1968 , Paper II - 4B - 2 . Defense 12. Kotlensky , W. V .; and Pappis , J .: Mechanical Properties of CVD Infiltrated Composites . Proceedings of 9th Biennial Conference on ...
Page 36
... exhibit significantly improved tensile strengths . The reported moduli for vapor- grown fibers are comparable to carbonized PAN fibers , but their tensile strengths are slightly lower . As expected , isotropic pitch fibers exhibit the ...
... exhibit significantly improved tensile strengths . The reported moduli for vapor- grown fibers are comparable to carbonized PAN fibers , but their tensile strengths are slightly lower . As expected , isotropic pitch fibers exhibit the ...
Page 37
... exhibit a thermal conductivity that is three times that of copper . Summary The precursor fibers used to produce current commercial carbon fibers are produced by melt , melt - assisted , and solution spinning . Melt spinning normally is ...
... exhibit a thermal conductivity that is three times that of copper . Summary The precursor fibers used to produce current commercial carbon fibers are produced by melt , melt - assisted , and solution spinning . Melt spinning normally is ...
Page 48
... exhibit either radial , flat - layer , or random microstructures , and these three formations appear to be the preferred microstructures of mesophase pitch . Endo ( ref . 15 ) showed that Carbonic pitch - based fibers have a radial ...
... exhibit either radial , flat - layer , or random microstructures , and these three formations appear to be the preferred microstructures of mesophase pitch . Endo ( ref . 15 ) showed that Carbonic pitch - based fibers have a radial ...
Page 58
... hand , fibers with microstructures that impede the development of an extended graphitic structure should exhibit higher compressive strengths . PAN - Based Carbon Fibers Johnson has used a single 58 CC Materials and Composites.
... hand , fibers with microstructures that impede the development of an extended graphitic structure should exhibit higher compressive strengths . PAN - Based Carbon Fibers Johnson has used a single 58 CC Materials and Composites.
Other editions - View all
Common terms and phrases
3-D braid alignment anisotropic applications approximately basal planes bonding borate borate glasses carbon fibers ref carbon matrix Carbon-Carbon Composites CC composites CC materials Chemical Vapor Deposition Composite Materials compressive strength cracks crystallites densification density effective elastic modulus fiber architecture fiber axis fiber bundle fiber surface fiber-reinforced filament geometry graphite heat treatment high modulus high temperatures high-performance impregnation increase interface isotropic knit laminate layer planes matrix matrix composites matrix material mechanical properties mesophase pitch method microcracks microstructure noncircular outer coating oxidation oxygen PAN fibers PAN precursor fiber PAN-based carbon fibers PAN-based fibers percent phenolic pitch matrix pitch-based carbon fibers pitch-based fibers polymer preform pressure produce pyrolysis pyrolytic carbon rayon reinforced resin result shear strength shown in figure SiO2 stiffness structure substrate techniques tensile modulus tensile strength thermal expansion thermoset thickness transverse unit cell weave woven yarn
Popular passages
Page 102 - Processing-Proceedings of 1987 International SAMPE Metals Conference, August 18-21, 1987. Bibliography A. Chou, TW; and Ko, FK: Textile Structural Composites . Elsevier, 1988. B. Hearle, JWS; Grosberg, P.; and Backer, S.: Structural Mechanics of Fibers, Yarns nd Fabrics. John Wiley & Sons, 1969. C. Kaswel, ER: Wellington-Sears Handbook of Industrial Textiles. West Point Pepperell, Inc., 1963. D. Klein, AJ: Which Way to Weave. Adv. Mater. & Process., vol. 2, no. 3, 1986, pp. 40-43.
Page 72 - On the basis of structural integrity and fiber linearity and continuity, fiber architecture can be classified into four categories: discrete, continuous, planar interlaced (2-D), and fully integrated (3-D) structures. In table I, the nature of the various levels of fiber architecture is summarized (ref.
Page 8 - In the thermal gradient technique (fig. 9), the part to be infiltrated is supported by a mandrel that is inductively heated. Therefore, the hottest portion of the substrate is the inside surface, which is in direct contact with the mandrel. The outer surface of the low-density substrate is exposed to a cooler environment and results in a temperature gradient through the substrate thickness. Surface crusting is eliminated because the deposition rate is greater on the heated fibers near the mandrel,...
Page 14 - Bokros, JC: Deposition, Structure, and Properties of Pyrolytic Carbon.
Page 84 - Brochier (ref. 12), and SEP (ref. 13) and in Japan by Fukuta of the Research Institute for Polymers and Textiles (refs. 14 and 15). The structural geometries resulting from the various processing techniques are shown in figure 15 (ref. 16). Figures 16(a) and 16(b) show the single bundle XYZ fabrics in a rectangular and cylindrical shape. Figure 16(c) demonstrates the multiple-yarn bundle possibilities in the various directions; figure 16(d) shows the multidirectional reinforcement in the 3-D structure...
Page 95 - In this way, four inclined, unidirectional laminae formed a unit cell. Using classical laminate theory, the elastic moduli then can be expressed in terms of the laminae properties. From the preform processing science aspect, Ko et al. (ref. 45) developed a fabric geometric model (FGM) based on the unit cell geometry shown in figure 26. The stiffness of a 3-D braided composite was considered to be the sum of stiffnesses of all its laminae. The unique feature of the FGM is its ability to handle 3-D...
Page 73 - A discrete fiber system such as a whisker or fiber mat has no material continuity; the orientation of the fibers is difficult to control precisely, although some aligned discrete fiber systems have recently been introduced. The structural integrity of the fibrous preform is derived mainly from inter-fiber friction. The strength translation efficiency, or the fraction of fiber strength translated to the non-aligned fibrous assembly of the reinforcement system, is quite low.
Page 88 - The major distinctions of these fabrics are the linearity of the bias yarns, the number of axes, and the precision of the stitching process.
Page 251 - ... to 1 14). Figure 14 shows the type of forced-flow thermal gradient arrangement currently being used for rapid CVI within deposition chambers at General Atomics. Temperature Limitations Current Coatings Although actual temperature limitations on the coatings currently being used for CC oxidation protection will vary depending on specific operating conditions and component performance requirements, general guidelines can be established based on experimental observations and the known thermochemical...