Mechanical, physical properties and tribological behaviour of silicon carbide composites with addition of carbon nanotubes

Four types of silicon carbide/carbon nanotubes composites were prepared with the main aim to develop ceramics with enhanced electrical conductivity. The SiC/CNT composites were prepared by in-situ growth of CNT on the SiC powder grains. Three types of SiC/CNT composites, where the precursor SiC/CNT powder mixture was prepared by Catalytic Chemical Vapour Deposition (CCVD) method and different amounts of Fe catalytic nanoparticles (2.5, 5, 10 wt% Fe), were designed. In addition, one reference material containing 2.5 wt% Fe catalytic nanoparticles but without CCVD application, i.e. without CNT, was prepared in order to correctly assess the role of CNT. The experimental materials were compacted by hot pressing (1850 °C/Ar/60 min/40 MPa). Mechanical properties such as hardness and elastic modulus of experimental materials were determined. Electrical conductivity as a function of CNT content was measured. The effect of the CNT addition on tribological properties (coefficient of friction, wear) of SiC/CNT composites was also observed.