Microstructure and Properties of C/SiC-Diamond Composites Prepared by the Combination of CVI and RMI

Diamond modified continuous carbon fiber reinforced silicon carbide (C/SiC-Diamond) composites are prepared using a combination of chemical vapor infiltration (CVI) and reactive melt infiltration (RMI). The effect of the diamond particle size on the microstructure, mechanical properties, and thermophysical properties of C/SiC-Diamond composites are investigated. A density of 2.05 g cm(-3) is achieved for C/SiC-Diamond composites impregnated with 1 mu m diamond particles. A near twofold enhancement of the thermal conductivity (9-10 W (m K)(-1)) and thermal diffusion coefficient (5 mm(2) s(-1)) is obtained, compared with continuous carbon fiber reinforced silicon carbide (C/SiC) composites (5-6 W (m center dot K)(-1)) prepared by CVI. It is established that the introduction of diamond can improve the thermal conductivity of C/SiC composites and increase the application potential in rocket engines, aerospace vehicles, and brake materials.