Synthesis Of ZrO₂-SiC Composite Powder And Its Application

In recent decades, both SiC and ZrO2 products have been widely applied. However, the further application of the SiC and ZrO2 products is limited because of their disadvantages such as complicated manufacture process, serious pollution and high cost etc. Therefore, it is significant to find a new process to manufacture SiC and ZrO2, which is simple, low polluted and cheap enough.In this study, the effects of heating temperature and adding catalyst on the synthesis of ZrO2-SiC composite powder by carbothermal reduction reaction were investigated by using X-ray-diffraction and scanning electronic microscope, and the thermodynamic analysis about the carbothermal reduction reaction of zircon was discussed. In addition, the influence of ZrO2-SiC composite powders addition on the thermal-shock resistance and oxidation resistance of Al2O3-C refractories was investigated. The research results were achieved as follows:(1) In the case of lg(pSiO/p(?)) and lg(pZrO/p(?)) ranged from-2 to 0, the theoretical synthesized temperature of ZrO2-SiC composite powder was 1544℃～1653℃.(2) Higher temperature was favored to yield ZrO2-SiC composite powder, but the ZrC was appeared up to 1650℃.(3) The addition of La2O3 was helpful to prepare ZrO2-SiC composite powder, and the effect was enhanced with increasing the amount of La2O3.(4) Both thermal-shock resistance and oxidation resistance of Al2O3-C refractories were improved by adding ZrO2-SiC composite powder, the optimum amount of ZrO2-SiC composite powder was 6mass% in this study.