ISSN:
1573-4803
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
Notizen:
Abstract The available information on the structure and properties of high strength carbon fibres is reviewed, and some new data are presented, showing the effects of boron doping and neutron irradiation on the properties of PAN-based carbon fibres. Theories relating the Young's modulus of the fibre to its microstructure are examined, and it is concluded that their relationship is qualitatively understood. Variations in electrical resistivity with different treatments may also be explained satisfactorily, again, in qualitative terms. The strength of carbon fibres is less well understood, however. It has been suggested that the fibre strength is governed by the presence or absence of stress-raising flaws, but while it is clear that such flaws can markedly reduce the strength, there is no clear estimate of the strength of an unflawed fibre. In this paper, we examine an alternative failure mechanism, initiated by shearing of the graphite crystallites in the fibre, and we conclude that such a mechanism may control the strength of the more graphitic fibres. Increases in the strength of carbon fibres may thus be achieved, not only by reducing the number and severity of the flaws, but also by applying the principles of solid-solution or dispersion hardening, and by reducing the graphite crystallite size (“grain refining”).
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00550292
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