Microstructure and mechanical properties of SiC and carbon hybrid fiber reinforced SiC matrix composite

Silicon carbide (SiC) matrix composite reinforced by both SiC and carbon fibers ([SiC-C]/pyrolytic carbon [PyC]/SiC) was fabricated by chemical vapor infiltration for reducing matrix microcracks. Microstructure, mechanical properties, and oxidation resistance of the composite were compared with those of C/PyC/SiC and C/PyC^HT/SiC composites in which PyC interphase was untreated and heat-treated at 1800°C in argon, respectively. Compared with the C/PyC/SiC composite, (SiC-C)/PyC/SiC composite shows considerable improvements in flexural strength, fracture toughness, and oxidation resistance. The different mechanical behaviors of the three composites were analyzed based on the He and Hutchinson's model.