Thermomechanical characterisation of coal tar pitch- based carbon containing SiC nanoparticles

Abstract

Coal tar pitch (CTP) modified with silicon carbide nanoparticles (nSiC) was used as a carbon binder precursor for the manufacture of carbon materials. Carbon samples were prepared in the form of a composition consisting of synthetic coke, graphite and nSiC- modified CTP prior to heat treatment at temperatures from 800°C to 2800°C. The effect of ceramic nanofiller in CTP on oxidation resistance of carbon samples obtained at various temperatures was studied. Physical and mechanical properties of carbon samples obtained at 2000°C and 2800°C were analysed. nSiC presence in CTP was found to change the elevated temperature properties of carbon samples. The oxidation tests conducted at 600°C in air showed a significant improvement of the resistance of carbon samples modified with small amount of nSiC and annealed at 2000°C. Properties investigated included characteristics important for application of carbon materials for carbon electrode manufacturing, i.e., electrical and thermal conductivities as well as mechanical properties. Due to microstructural changes of carbon samples in the presence of nSiC filler physical and mechanical properties improved after annealing the samples at high temperature in comparison to unmodified carbon samples.