Toughening of carbon fiber/pitch-based carbon matrix composites by microspace control

Abstract A relation between the pore structure and the fracture resistance is examined on carbon fiber/pitch-based carbon matrix composites since pores are considered an important microspace component affecting the fracture behavior in the composites. A part of the pores may lie on a fiber surface so that the bonding force at the fiber/matrix interface is varied depending on the size and the spatial distributions of the pores. The change in the bonding force distribution brings a large-scale fiber pullout process into the composites. Therefore, the fracture resistance can be improved by controlling the microspace of the composites.