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Carbon fiber-reinforced SiC composites were prepared by precursor pyrolysis-hot pressing (PP-HP) and precursor impreg- nation-pyrolysis (PIP), respectively. The effect of fabrication methods on the microstructure and mechanical properties of the compo- sites was investigated. It was found that the composite prepared by PP-HP exhibits a brittle fracture behavior, which is mainly as- cribed to a strongly bonded fiber/matrix interface and the degradation of the fibers caused by a higher processing temperature. On the contrary, the composite prepared by PIP shows a tough fracture behavior, which could be rationalized on the basis of a weakly bonded fiber/matrix interface as well as a higher strength retention of the fibers. As a result, in comparison with the composite pre- pared by PP-HP, the composite prepared by PIP achieves better mechanical properties with a flexural strength of 573.4 MPa and a fracture toughness of 17.2 MPa·m1/2.
Carbon fiber-reinforced SiC composites were prepared by precursor pyrolysis-hot pressing (PP-HP) and precursor impregation-pyrolysis (PIP), respectively. The effect of fabrication methods on the microstructure and mechanical properties of the compo- sites was investigated It was found that the composite prepared by PP-HP exhibits a brittle fracture behavior, which is mainly as- cribed to a strongly bonded fiber / matrix interface and the degradation of the fibers caused by a higher processing temperature. On the contrary, the composite prepared by PIP shows a tough fracture behavior, which could be rationalized on the basis of a weakly bonded fiber / matrix interface as well as a higher strength retention of the fibers. As a result, in comparison with the composite pre- preared by PP -HP, the composite prepared by PIP achieves better mechanical properties with a flexural strength of 573.4 MPa and a fracture toughness of 17.2 MPa · m1 / 2.