Fabrication of diamond/SiC composites by Si-vapor vacuum reactive infiltration

Diamond/SiC composites were fabricated by a rapid gaseous Si vacuum reactive infiltration of porous carbon-containing diamond preforms at 1600 °C for 1 h. The obtained composites consisted of diamond, β-SiC and a small fraction of residual unreacted Si; nearly fully dense composites were achieved. Graphitization of diamond did not occur during the infiltration at 1600 °C under vacuum. The transgranular fracture mode of diamond crystals and the perfect interface between diamond and SiC suggested a strong interfacial bonding strength. Relatively-low coefficient of thermal expansion (3.6×10−6/K, 50–400 °C) and high thermal conductivity (562 W/m K) of diamond/SiC composites showed great potential for thermal management applications.