Accession Number:

ADA235633

Title:

Preparation and Characterization of Carbon Filaments

Descriptive Note:

Final rept. 1988-1991

Corporate Author:

COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS

Personal Author(s):

• Patel, Dinesh
• McConica, Carol

Report Date:

1991-04-01

Pagination or Media Count:

261.0

Abstract:

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.

Descriptors:

• *CARBON FIBERS
• COMPRESSIVE PROPERTIES
• MECHANICAL PROPERTIES
• MICROSTRUCTURE
• CONTRACTS
• PREPARATION
• STRUCTURES
• MODULUS OF ELASTICITY
• DIAGNOSIS(GENERAL)
• FILAMENTS
• NOISE
• LOW FREQUENCY
• TORSION
• NOISE(ELECTRICAL AND ELECTROMAGNETIC)
• DIAMETERS
• FIBERS

Subject Categories:

• Ceramics, Refractories and Glass

Distribution Statement:

APPROVED FOR PUBLIC RELEASE