Pitch resin addition induced evolution of composition, microstructure and mechanical property of C/C-SiC-ZrC composites

Abstract

Precursor infiltration and pyrolysis (PIP) has been widely used to fabricate C/C-SiC-ZrC composites. However, the use of organic polymeric precursor of zirconium carbide (PZC) can usually cause the degradation of their mechanical property due to the reaction of ZrO2 intermediate with pyrocarbon (PyC) and carbon fibers (Cf) during pyrolysis. In this study, pitch resin was directly added into the mixture solution of PZC and polycarbosilane (PCS) to supply extra carbon. The composition, microstructure and mechanical property of the as-prepared composites were investigated systematically. The pure ZrC-SiC with a high ZrC content is obtained at 1500 °C when the PZC/PCS/resin mass ratio is 20:1:5. The resulting C/C-SiC-ZrC composites have the highest flexural strength of 247.4 MPa since the degradation of PyC and Cf is greatly alleviated by the addition of resin. The damage mechanism of PyC and Cf during pyrolysis was revealed under the different fabrication conditions.