The Effect of Nanosized Carbon Black on the Physical and Thermomechanical Properties of Composite

The effects of using nanosized carbon black in the range of 0–10 weight percentages on the physical and thermomechanical properties of Al2O3-SiC-SiO2–graphite refractory composites were investigated. Nanosized carbon black addition improved the relative heat resistance and oxidation resistance of composites. The bulk density of the composites is reduced with increasing carbon black (CB) content. Increase in CB content first causes an increase in the apparent porosity, but at more than 3 wt% amount of CB, a decrease of apparent porosity was observed. The cold crushing strength (CCS) increased with increasing CB content in samples fired at 800∘C and in samples fired at 1500∘C when the content is increased to 3 wt%, but the CCS decreased with increasing CB content in samples fired at 1500∘C when the CB content was less than 3 wt%. The composite without CB exhibits the highest value of CCS at firing temperature of 1500∘C