Abstract: ZrC-ZrB2-SiC were fabricated by in-situ reaction synthesis using zircon,B4C and coke as raw materials in Al2O3-C refractories.Effect of zircon,B4C and coke additions and temperature on resultant phases was analyzed by XRD.The influence of ZrC-ZrB2-SiC on oxidation resistance of Al2O3-C refractories was studied by XRD and SEM.The mechanism of oxidation resistance was further analyzed.The results show that ZrC-ZrB2-SiC were synthesized in Al2O3-C refractory matrix with the zircon-B4C-coke composite powder addition of 20;, temperature of 1550 ℃, holding time of 3 h.The oxidation resistance of Al2O3-C refractory can be improved significantly.ZrC-ZrB2-SiC formed a dense protective layer and preventing further oxidation of the material.

Key words: ZrC-ZrB2-SiC were fabricated by in-situ reaction synthesis using zircon,B4C and coke as raw materials in Al2O3-C refractories.Effect of zircon,B4C and coke additions and temperature on resultant phases was analyzed by XRD.The influence of ZrC-ZrB2-SiC on oxidation resistance of Al2O3-C refractories was studied by XRD and SEM.The mechanism of oxidation resistance was further analyzed.The results show that ZrC-ZrB2-SiC were synthesized in Al2O3-C refractory matrix with the zircon-B4C-coke composite powder addition of 20;, temperature of 1550 ℃, holding time of 3 h.The oxidation resistance of Al2O3-C refractory can be improved significantly.ZrC-ZrB2-SiC formed a dense protective layer and preventing further oxidation of the material.