Carbon-Felt, Carbon-Matrix Composites: Dependence of Thermal and Mechanical Properties on Fiber Precursor and Matrix Structure

Abstract

Properties of carbon-felt, pyrolytic carbon-matrix composites have been measured as a function of fiber precursor [rayon and polyacrylonitrile (PAN)] and matrix microstructure (smooth laminar, rough laminar, and isotropic). The primary matrix effect is caused by the graphitic nature of the heat-treated rough laminar matrix which yields a high composite thermal conductivity. The increased modulus of the PAN-based fibers results in increased composite strength and modulus and a significantly reduced thermal expansion. A heat-treated, PAN-based carbon felt, rough laminar carbon matrix composite has a superior thermal shock figure-of-merit based on these results.