Mechanical properties of a 3D needled C/SiC composite with graphite filler

A three-dimensional (3D) needled carbon/carbon (C/C) preform was achieved after one cycle of precursor infiltration-pyrolysis. The mixture of phenolic resin and 8 vol% graphite with an average particle size of 2.5 μm was employed as the carbon precursor. The C/SiC composite, made from the as-obtained C/C preform infiltrated with liquid silicon, was mechanically characterized under flexural loading. The results show that the material exhibited pseudo-plastic fracture characteristic and had the average strength of 120 MPa. A major portion of the toughness was attributable to fiber elastic bridging and frictional pullout and the crack deflection and pinning in the matrix. Flake graphite had tailored the carbon-rich interfacial layer and increased the toughness of the brittle matrix.