Influence of Heat Treatment of the Matrix on the Physical Properties of Carbon-Carbon Composites

摘要

The effects of heat treatment on Carbon-Carbon composites have been studied on small composite samples by the use of X-ray diffraction, microstructural analysis (optical and scanning electron microscopy), density measurements, and sonic resonance for determining modulus. Modulus values for small samples of three-dimensional composites give good agreement with rule of mixtures estimates when the actual fiber volume fraction of the small sample is used. Heat treatment of pyrolyzed two-dimensional laminates shows initially a drastic in drop in modulus, corresponding to pyrolysis, decreasing density, and increasing porosity. In the graphitization temperature range, however, some increases are seen in modulus, accompanied by decreasing graphite c-spacing and increasing graphitization. Microstructural examination also shows evidence of increasing graphitization of the matrix, accompanying the increase of stiffness. Keywords: Carbon-carbon Composites, Carbon fiber, Dynamic modulus, Heat treatment.