SiC-coated carbon nanotubes and their application as reinforcements for cemented carbides

Multi-walled carbon nanotubes (MWCNTs) were coated with a nanometer sized SiC layer by the reaction of SiO(g) and CO(g). The onset temperature of oxidation increased from 560 to 700 °C with the SiC coating. Composites made from SiC-coated MWCNTs dispersed in WC–10 wt.%Co were successfully sintered at the low temperature of 1050 °C using the pulsed electric current sintering. The microhardness of these composites was 20 GPa, which is 2.5 GPa (14%) higher than that of WC–10 wt.%Co.