Thermal conductivity of unidirectional carbon/carbon composites with different carbon matrixes

Unidirectional carbon/carbon preforms were densified using resin and mesophase pitch, respectively. The microstructure and thermal properties of the carbon/carbon composites with different carbon matrixes were investigated. The results show that resin carbon has a lower micro-orientation (micro-graphitization degree) and combines loosely with carbon fibers, having obvious interface cracks. Due to the specific properties of mesophase pitch, it can arrange along the axis of carbon fibers during carbonization and combines closely with carbon fibers. The thermal conductivity of composites with mesophase pitch matrix is higher than that of composites with resin matrix, whether in the direction along the fiber axis or in the direction perpendicular to the fiber axis.