Thermal/mechanical properties of short carbon fibre/SiC co-reinforced graphite matrix composites produced by low temperature hot pressing

Short carbon fibre and silicon carbide (SiC) co-reinforced graphite matrix composites were prepared with natural flaky graphite as raw materials by low temperature hot pressing at 1900 degrees C. The flexural strength in the direction perpendicular to the graphite layers reached 221 MPa for carbon fibre of 5 vol% and SiC of 30 vol%, which was an improvement of 275% compared with pure graphite materials. The composites improved the bend strength of the block obviously, while maintaining the thermal conductivity of 220 W/m K in the direction perpendicular to the hot pressing. The new process has the advantages of being a non-pitch binder process which avoids the high temperature graphitisation operation.