一维或二维结合相对含碳耐火材料强度和韧性的影响

Effect of one/two-dimensional bonding phases on strength and toughness of carbon-containing refractories

含碳耐火材料在高温下会发生酚醛树脂结合剂炭化和氧化物的还原反应,从而生成含碳气相或亚稳态氧化物气相,通过高温原位催化技术,可有效实现这些气相成分沉积生长,促进一维或二维结合相的原位生成,从而显著改善含碳耐火材料特别是低碳材料的强度和韧性。研究发现:1)酚醛树脂在高温下可形成碳纳米管结构,其氧化峰值温度可从506℃提高到664.6℃;2)MgO-C耐火材料中可原位形成一维MgO晶须或MgAl_2O_4晶须,其常温抗折强度、常温耐压强度、断裂位移量和经1100℃■水冷热震循环2次后残余耐压强度分别提高66%、47%、13%和26%;3)Al_2O_3-C耐火材料中可原位形成二维片状β-SiAlON阵列结构,而二维阵列结合相的生成,可将材料强度提高60%以上,1100℃■水冷热震循环2次后残余耐压强度仅降低4.5MPa。可见,含碳耐火材料中一维或二维结合相的高温原位生成,可显著改善含碳耐火材料的综合物理性能,是耐火材料低碳化增强和增韧的发展方向。

Gaseous phases of carbon-containing and metastable oxides will be resulted from the carboniza-tion of phenolic resin binders and the reduced reactions between C and oxides at high temperatures in car-bon-containing refractories. With the in-situ catalysis technique,these gaseous phases can be transformed to oneor two-dimensional bonding phases by deposition, which is favorable for the improvement on strength and toughness of carbon-containing refractories,especially low carbon refractories. The research results reveal that： 1） the amorphous carbon resulted from phenolic resin can be transformed to carbon nano tubes,thus,the oxidation peak temperature is raised from 506 to 664.6 °C; 2）one-dimensional whisk-ers of MgO or MgAI204 can be in-situ formed in MgO-C refractories,and their CMOR,CCS,rupture dis-placement and residual CCS（two water quenching cycles,1 100 ℃） are increased by 66% ,47% ,13% and 26% respectively; 3）two-dimensional array structure of flake （3-SiAION can be /n-s/fu formed in Al203-C re-fractories, which improves the material strength 60% and decreases the residual strength after thermal shock by only 4.5 MPa. It is believed that the in-situ formation of oneor two-dimensional bonding phases at high temperatures can improve the comprehensive thermal physical properties of carbon-containing re-fractories, and will be the developing trend of the strengthening and toughening of low carbon-containing refractories.