Accession Number : ADA195073

Title :   Transverse Expansion of Individual Carbon and Graphite Filaments,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA MATERIALS SCIENCES LAB

Personal Author(s) : Sheaffer, Patrick M

PDF Url : ADA195073

Report Date : 22 Apr 1988

Pagination or Media Count : 24

Abstract : The laser diffraction technique for measuring the diameter of fine filaments has been adapted for measuring the transverse coefficient of thermal expansion (CTE) of individual carbon and graphite filaments. CTE was measured on three types of polyacrylonitrile (PAN)-derived filaments and one type of pitch-derived filament that had already been heat-treated to 2600 C. The measurements are unique because the filaments were in a surface-traction-free environment; the data are therefore inherently more accurate than those obtained by conventional methods. Significant variations in the transverse CTE of pitch-based filaments were observed; they have been attributed to local differences in the (transverse) preferred orientation of the graphite layer planes in those filaments. Individual pitch-based filaments were found to twist about their axis when constrained at both ends and heated; the center of the filament presumably undergoes maximum deflection. Keywords: Thermal expansion, Thermal strain, Carbon filaments, Carbon fibers, Composites, Graphite Fibers.

Descriptors :   *CARBON FIBERS, *FILAMENTS, *GRAPHITE, CARBON, COEFFICIENTS, DEFLECTION, DIFFRACTION, EXPANSION, FINE GRAINED MATERIALS, LASERS, THERMAL EXPANSION, THERMAL STRESSES, TRANSVERSE, CARBON REINFORCED COMPOSITES

Subject Categories : Refractory Fibers
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE