Microstructure and physical properties of SiC_f/SiC composites fabricated by the CVI/LSI/PIP hybrid process

The mechanical properties of SiC_f/SiC composites depend on the microstructure of matrix, fiber and interphase. Therefore, the technology to control the microstructure of those components can be key to determining its application in the future. In this study, SiC_f/SiC composite with a fiber volume fraction of 30 vol% was prepared using the CVI/LSI/PIP hybrid process. The apparent density and residual silicon of the prepared composite were measured to be 2.77 g/cm³ and 2 vol%, respectively. As a result of evaluatingthe tensile strength, the elastic modulus, PLS, and UTS of the SiC_f/SiC composite at 1400 °C were measured to be 152.3 GPa, 125.1 MPa, and 144.1 MPa, respectively. Additionally, the crystallinity of the PyC interphase in SiC_f/SiC composites was quantified using HRTEM, and the effect of the microstructure of the SiC matrix and PyC interphase on the mechanical properties discussed.