Microstructure and mechanical properties of three-dimensional needled C/SiC composite

A three-dimensional needled carbon fiber reinforced silicon carbide (3D needled C/SiC) ceramic matrix composite in the through-the-thickness direction was fabricated by the chemical vapor infiltration process. The resulting composite has a bulk density of 2.15 g/cm³ and an open porosity of 16%. The adjacent layers for thickness direction in the 3D needled C/SiC composite are interlinked perfectly together by needling fibers and this greatly improves the interlaminar shear strength of the composite. The interlaminar shear strength of the 3D needled C/SiC composite is 95 MPa (improved 171.4% compared with 2D C/SiC composite, 35 MPa), and the tensile strength and flexural strength of the 3D needled C/SiC composite are 159 MPa and 350 MPa, respectively. The composite exhibits a non-brittle failure behavior including propagation and deflection of cracks, fracture and pullout of fibers.