Effect of carbon fiber pre-heat-treatment on the microstructure and properties of Cf/SiC composites

Three-dimensional braided carbon fiber reinforced silicon carbide (3D-Cf/SiC) composites were fabricated by precursor infiltration and pyrolysis (PIP) method, where the carbon fiber was heat treated at 1673 K under vacuum before PIP process. The effects of the pre-heat-treatment process on the properties and the microstructure of Cf/SiC composites were investigated through SEM, TEM and HRTEM analysis. The results show that pre-heat-treatment of carbon fiber leads to excellent properties of Cf/SiC composites, with the bending strength of 600.8 MPa, the shear strength of 45.9 MPa, and the fracture toughness of 18.5 MPa m1/2.