Effect of nano-SiC on the sintering behavior and properties of calcined carbon derived from mesocarbon microbeads

Calcined carbon materials derived from mesocarbon microbeads (MCMBs) with or without pre-oxidative treatment were prepared and the effect of doped nano-SiC powder on the sintering behavior and properties was investigated. The results showed that the sintering shrinkage and density increment of the samples doped with 5 wt.% nano-SiC were higher than those with 3 wt.% and 10 wt.%, due to the amount of defects and extent of graphitization controlled by the content of nano-SiC. Physical and mechanical properties improved remarkably after doping a certain amount of nano-SiC. The highest bending strength of 122 MPa and lowest electric resistivity of 28 μΩ m were obtained when doping 5 wt.% nano-SiC in green MCMBs. Ball-milling contributed to reduction of particle sizes of MCMBs/nano-SiC mixtures and hence reduced or eliminated the gaps between particles in the calcined materials. The catalytic effect of nano-SiC can promote particle rearrangement and structure improvement during the sintering.