Property evolvements in SiCf/SiC composites fabricated by combination of PIP and electrophoretic deposition at different pyrolysis temperatures

摘要

Three-dimensional four-directional (3D4d) braided SiCf/SiC composites were prepared by combination methods of polymer impregnation and pyrolysis (PIP) and electrophoretic deposition (EPD). Differences in the mechanical properties between the composites manufactured at different pyrolysis temperatures were investigated. Mechanical properties decreased significantly as the sintering temperature increased, mainly due to the degradation in the mechanical properties of the KD-II fibers and the increasing defects. Thermal conductivities of the composites were characterized as well. The results indicated that, due to a higher degree of crystallization of the matrix derived from the precursor, thermal conductivities of the composites greatly increased with the increasing pyrolysis temperature. Especially when the pyrolysis temperature was 1800 degrees C, the thermal conductivity reached a relatively high value of 43.15 W/(m.K) at room temperature.