Effect of heat treatment temperature on the fracture characteristics of carbon/carbon composite discs

Tensile properties and fracture morphologies of C/C composites used as aircraft brake disc at different heat treatment temperature have been studied. Fracture morphologies characteristics of tensile sample were observed with scanning electron microscope (SEM), and fracture mechanism was analyzed. The test results show that, with increase of heat treatment temperature, tensile strength of C/C composites has a descend trend, whereas, breaking strain has an upward trend, and failure mode changes from brittle fracture into "pseudo-plasticity" fracture. Destructional form includes interface debonding, extraction, break and matrix damage and so on, among which interfacial failure is principal fracture mechanism.