Effects of heat treatment temperature on mechanical properties of mesophase pitch-based C/C composites

The effects of final heat treatment temperature on the microstructure, mechanical properties and fractured surface image of mesophase pitch-based 2D C/C composites were studied by three-point bending, XRD and SEM test, and the fracture mechanism was investigated. The results show that the graphitization degree and microcrystal size (L_c) increase, interlayer distance (d₀₀₂) decrease with the increase of final heat treatment temperature of the C/C composites. The interface bonding strength weakens with the increase of heat treatment temperature. The flexural strength of composites after heat treatment is lower than that of untreated, the fracture characters of composites are changed from the brittle fracture to like-tough.