Effect of granular reinforcements on the properties of pitch-based carbon composites

Pitch-based carbon composites (PCCs) reinforced by three granular cokes, metallurgical coke, No.1 pitch coke and No.2 pitch coke, were prepared under an air atmosphere using a hydraulic press and new mold pressing and semi-carbonization shaping technology. The as-fabricated PCCs were treated in turn by quick baking, one-time densification and graphitization at 2373 K, and three corresponding samples were obtained. The effect of the type of granular coke used as reinforcement on the volume density and mechanical properties of the PCCs was studied by a materials testing machine, SEM, and XRD. Results indicate that the compressive strength of the PCCs is closely related to the surface morphology, microstructure, and compressive strength of the granular cokes. A higher compressive strength, coarser surface and more open porosity of granular cokes induce higher reinforcement to the composites. The PCCs can be obtained through baking, densification, and graphitization. The compressive strength of the PCCs fabricated using metallurgical cokes is the highest with those from No.2 pitch coke in the middle and those from No.1 pitch coke the lowest. The granular cokes not only greatly influence the mechanical properties of the PCCs, but also, to some extent, pass their original strength to their descendants.