Preparation and Characterization of Carbon Filaments
Final rept. 1988-1991
COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS
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The final report for our contract Preparation and Characterization of Carbon Filaments is presented. We have performed important and extensive research on Catalytic Chemical Vapor deposited fibers with comparative work on ex-polymer fibers. A new diagnostic technique has been developed involving low frequency electrical noise in carbon fibers. The exciting results from this technique infer microstructure properties as inter-ribbon and inter-layers are probed. Mechanical properties including Youngs modulus, torsional modulus and compressive properties have been measured also on CCVD filaments. We have proved that Youngs modulus of CCVD fibers generally decrease with diameter. However, increases in the Youngs modulus of CCVD fibers generally decrease with diameter. However, increases in the Youngs modulus for a small range of diameters may be present due to separating entities during the growth of CCVD fibers. Higher torsional moduli were also measured for these annular structures. Typical values were as high as one quarter theoretical maximum for a perfectly ordered system. Temperature dependent piezoresistance was observed for the first time in high moduli fibers.
- Ceramics, Refractories and Glass