摘要
以电熔白刚玉、电熔莫来石、氧化铝微粉、二氧化硅微粉和硅溶胶为主要原料,制备了硅溶胶、二氧化硅微粉结合刚玉浇注料以及硅溶胶结合刚玉-莫来石浇注料,研究了不同温度处理后浇注料的常温性能、冷态和热态抗折强度以及弹性模量等性能,并进行了差热、X射线衍射和显微结构分析。研究结果表明:1)与二氧化硅微粉相比,硅溶胶能够显著提高浇注料800℃以下的抗折强度;硅溶胶结合和二氧化硅微粉结合的机制以及随温度变化的规律基本一致。2)高温下刚玉骨料中β-Al2O3分解产生的Na2O大部分进入液相,使液相中Na2O含量增加,不利于浇注料中原位生成莫来石,并降低材料的高温强度。3)莫来石加入到硅溶胶结合刚玉浇注料中,能显著降低浇注料的弹性模量,借助于高温下液相的传质作用,莫来石彼此连接形成网络,从而增加了浇注料的强度。
Silica sol bonded corundum castables, microsilica bonded corundum castables, and silica sol bonded corundum-mullite castables were prepared using white fused alumina,fused mullite,ultra-fine alumina,microsilica and silica sol as main starting materials. Conventional properties,cold and hot modulus of rupture and elastic modulus of the castables after firing at different temperatures were researched. Some specimens were analyzed by DTA,XRD and SEM. The results show that： （ 1 ） compared with microsilica,silica sol can significantly improve the modulus of rupture of the castables below 800 ℃, and the bonding mechanisms of silica sol and microsilica and their variation tendencies with temperature are basically the same;（2） at high temperatures most of the sodium oxide from the decomposition of β-Al2O3 in fused alumina aggregate enters into the liquid to increase the sodium oxide content in the liquid which is disadvantageous for the formation of in-situ mullite and hot modulus of rupture; （3） elastic modulus of the silica sol bonded corundum castables is decreased by adding mullite, and the mullite network forms due to the mass transfer of liquid phase at high temperatures and reinforces the structure of the castables.
出处
《耐火材料》
CAS
北大核心
2012年第2期90-95,共6页
Refractories
