ZrB2-SiC复合粉体添加量对低碳镁碳耐火材料性能的影响

Effect of ZrB_2-SiC Composite Powder Addition Amount on Performance of Low Carbon Magnesium Carbon Refractory

以ZrB_2-SiC复合粉体替代鳞片石墨,在473K固化12h制备ZrB_2-SiC/MgO-C耐火材料,并分别在1 373,1 673K进行了热处理,研究了复合粉体添加量(质量分数在0~4.0%)对该耐火材料物理性能、力学性能和抗热震性能的影响。结果表明:随复合粉体添加量的增加,固化后和热处理后耐火材料的常温抗折强度和耐压强度均先增后降,热处理温度对常温物理和力学性能的影响很小;1 673K热处理后耐火材料的高温抗折强度均随复合粉体添加量的增加先增后降;1 673K热处理后耐火材料在测试温度低于673K时主要发生弹性变形,在测试温度不低于673K时则发生塑性变形;以ZrB_2-SiC复合粉体替代石墨能较大幅度地提高耐火材料在氧化气氛下的抗热震性能。

By the replacement of flake graphite with ZrB2-SiC composite powder,ZrB2-SiC/MgO-C refractories were prepared after curing at 473 Kfor 12 h,and then heat treated at 1 373 K and 1 673 K,respectively.The effects of addition amount（0-4.0 wt%）of the composite powder on the physical properties,mechanical properties and thermal shock resistance of the refractories were studied.The results show that with the increase of addition amount of the composite powder,the modulus of rupture and compressive strength at ambient temperature of the refractories after curing and after heat-treatment increased and then decreased.The heattreatment temperature had little effect on the physical and mechanical properties at ambient temperature.The modulus of rupture at elevated temperature of the refractories after heat-treatment at 1 673 Kincreased and then decreased with the increase of addition amount of the composite powder.The refractory after heat-treatment at 1 673 K mainly deformed in elasticity at testing temperatures below 673 Kand in plasticity at testing temperatures no lower than 673 K.The replacement of graphite with ZrB2-SiC composite powder greatly improved the thermal shock resistance in the oxidization atmosphere of the refractory.