Improved thermal shock stability and oxidation resistance of low-carbon MgO–C refractories with introduction of SiC whiskers

Abstract

This research focuses on the utilization of SiC whiskers synthesized from rice husk powders in low-carbon magnesia–carbon (MgO–C) refractories, and attempts to reduce the flake graphite content in refractories by adding synthesized SiC whiskers. The effect of the addition amount of SiC whiskers on the microstructure, mechanical properties, thermal shock stability and oxidation resistance of MgO–C refractories with different graphite content was studied. The results indicated that the introduction of SiC whiskers facilitated the generation and growth of ceramic phases in MgO–C refractories. By adding 1 wt% SiC whiskers, the graphite content could be reasonably reduced (from 5 wt% to 4 wt%), and the strength, thermal shock stability and oxidation resistance of refractories were enhanced by the synergistic effect of the introduced SiC whiskers and the generated ceramic phases, the CMOR, CCS, residual CCS, and oxidation resistance were increased by 44, 6, 12 and 27% respectively.