Accession Number:

ADA250285

Title:

Fundamental Study of Compressive Strength Development in PAN-Based Carbon Fibers

Descriptive Note:

Final technical rept. Dec 1988-Sep 1991

Corporate Author:

GEORGIA INST OF TECH ATLANTA SCHOOL OF CHEMICAL ENGINEERING

Report Date:

1992-03-20

Pagination or Media Count:

81.0

Abstract:

Evolution of mechanical properties in the conversion of two precursor polymeric fibers to carbon fibers has been studied. The focus has been on properties in axial compression of polyacrylonitrile PAN, a semi rigid polymer - and polybenzobisthiazole PBZT, a rigid rod polymer - based carbon fibers. Mechanical properties of fibers at different extents of progression toward the graphite fiber structure reveal that the evolutions of tensile and compressive properties are not synchronized. Substantial enhancements in both tensile and compressive strengths of carbon fibers occur only with the development of the carbonized morphology with its characteristic basal planes as the fundamental structural units. In addition, the recoil from tension method has been analyzed vis-a-vis axial compressive strength of carbon fibers. Fracture surfaces of specimens from this experiment do not necessarily reveal failure in a simple compression mode and especially includes bending. Statistical analysis of the recoil method demonstrates that the fiber failure distribution can be expressed by either a logistic or a Weibull distribution.

Subject Categories:

  • Refractory Fibers
  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE