以镁砂、鳞片石墨和ZrB₂-xSiC（x为0，20%，40%，60%，80%，100%，质量分数）复合粉为原料，经成型、干燥、固化和不同温度（1 373，1 673 K）保温3 h热处理后，制备得到ZrB₂-SiC/MgO-C低碳复合耐火材料，研究了SiC含量对该耐火材料物理和力学性能的影响。结果表明：随SiC含量的增加，固化后复合耐火材料的体积密度和常温抗折强度先增大后减小再略有增大，耐压强度则波动性降低，当SiC质量分数为20%时，复合耐火材料的常温性能最佳；在1 673 K保温3 h热处理后，复合耐火材料的抗折强度随温度的升高呈先增大后减小的变化趋势，当SiC质量分数为20%时，不同温度下的抗折强度均达到最大；SiC含量的改变对不同温度下的载荷和位移关系影响较小，复合耐火材料的塑性变形开始温度为873~1 073 K，断裂温度均为1 673 K。

Low carbon ZrB₂-SiC/MgO-C composite refractories were prepared after formation, drying, curing and heat treatment at different temperatures (1 373, 1 673 K) for 3 h with magnesia, flake graphite and ZrB₂-xSiC composite powders as raw materials, where x was equal to 0, 20wt%, 40wt%, 60wt%, 80wt%, 100wt%, respectively, and then the effects of SiC content on the physical and mechanical properties of the refractory were investigated. The results show that with the increase of SiC content, the bulk density and rupture strength at ambient temperature of the cured composite refractory increased and then decreased and then increased slightly while the compressive strength decreased in volatility. The performance at ambient temperature of the composite refractory with 20wt% SiC was the best. After heat-treatment at 1 673 K for 3 h, the rupture strength of the composite refractory increased and then decreased with increasing temperature, and the rupture strength at different temperatures all reached the largest values with 20wt% SiC. The change of SiC content had little influence on the relation between load and displacement at different temperatures. The plastic deformation starting temperatures of the composite refractories were 873-1 073 K and the fracture temperature was 1 673 K.