Microstructure and mechanical properties of coal tar pitch-based 2D-C/C composites with a filler addition

In order to improve the flexural and the inter-laminar shear strength of coal tar pitch-based 2D-C/C composites, fillers (carbon blacks and colloidal graphite) have been introduced between the UD layers before the first infiltration of pitch. Matrix parts made of the filler/pitch-based cokes showed fine mosaic microtextures. They were found at the interface between the layers. Whereas the tensile strength is not affected, the flexural strength and the ILSS were significantly increased by the addition of fillers. The original structure of the inter-layer matrix parts and the decrease of the number of flaws were found to be responsible for the improvement of the shear strength of the 0/90 degrees UD layers. (C) 2001 Elsevier Science Ltd. All rights reserved.