Stress graphitization

Inagaki, M. and Meyer, R.A. Stress graphitization. In Chemistry and Physics of Carbon, Vol. 26, New York Marcel Dekker, 1999 149. 

Stress Graphitization, Michio Inagaki and Robert A. Meyer... 

R.J. Zaldivar and G.S. Rellick, Some observations on stress graphitization in carbon-carbon composites. Carbon 29 [8] 1155-1163. 1991. 

Johnson JW, Marjoram JR, Rose PG, Stress graphitization of polyacrylonitrile based carbon fibre. Nature, 221, 357-358, 25 Jan 1969. 

Strong SL, Small-scale heat treatment of rayon precursors for stress graphitization, J Mater Sci, 9, 993-1003, 1974. 

Graphitization of a carbon-carbon composite has a greater effect on the matrix or fiber and occurs mainly in the matrix as a sheath, some 1-3 pm thick. This thermal expansion stress is termed stress graphitization [34]. Jortner depicts other forms of orientations (Figure 14.3) that have been observed [35]. 

S. Bonnamy, and P. G. Rouxhet Stress Graphitization, M. Inagaki and R. A. Meyer High Quality Graphite Films Produced from Aromatic Polyimides,... 

Liquid-crystalline mesophase pitch is employed for high modulus carbon fiber production by stress graphitization. Carbon fibers prepared from this process were commercialized in the early 1980s (1). Petroleum, coal tar, and polyCvinyl chloride) are common sources of the pitch used in the preparation of carbon fibers. 

The structural models for anisotropic polymeric carbon are compared in fig.9 with the isotropic types as discussed before. The first model was developed by ROLAND (26) for rayon based stress graphitized fibres (the early THORNEL-type fibres of UNION CARBIDE) from small angle scattering, electron diffraction and TEM. The idea of ribbon like polyaromatics was introduced by him. 

Stress graphitization refers to the solid-state transformation of non-graphitic carbon into graphite by heat treatment combined with application of mechanical stress, resulting in a defined degree of graphitizjation being obtained at a lower temperature and/or after a shorter time of heat treatment than in the absence of applied stress. 

Stress graphitization may also occur in volume elements of a carbon body in the process of heat treatment as a result of the action of internal residual or thermal stresses. 

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