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

摘要

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°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.