Microstructural Control of Carbon Fiber/Carbon Composites using High Carbon-yeild Pitches as Matrix Precursor

Abstract

Microstructural control of carbon fiber/carbon composites wasinvestigated by using high carbonyield pitches as matrix precursor, and by adding sulfur or carbon black to the precursor pitch. Using each precursor pitch the matrix carbon resulted in the flow-type microstructure where the carbon layers alligned extensively parallel to the carbon fiber axis, and hardly depended on the characteristics of the precursor pitch. However, the addition of sulfur or carbon black to the precursor pitch was effective in changing the matrix carbon into the fine mosaic microstructure where the size of the anisotropic region of the matrix carbon strongly depended on the characteristics of the precursor pitch and the type of the additives. These results suggested that the microstructure of carbon fiber/carbon composites with high carbon-yield pitch as matrix precursor could be controled by the addition of sulfur or carbon black.