【作者】 邹明；

【导师】 蒋明学； 李勇；

【作者基本信息】 西安建筑科技大学 ， 材料学， 2004， 硕士

【摘要】 本文通过相图分析和热力学计算设计了MgO-Al₂O₃-TiO₂系耐火材料的物相组成，其主晶相为方镁石和尖晶石固溶体，基质中结合相为高熔点的钛酸钙（CT）和镁橄榄石（M₂S）。 对不同配比和以不同生产工艺生产的镁铝钛耐火材料的性能和显微结构进行了研究，着重探讨了烧成温度、材料中TiO₂含量和Al₂O₃含量对镁铝钛试样性能和结构的影响。试验结果表明：1、随着烧成温度的升高，镁铝钛试样的显气孔率下降，体积密度增加；2、在同一温度下，随着试样中TiO₂含量的增加，材料的显气孔率下降，体积密度增加，热震稳定性提高；3、随着试样中Al₂O₃含量的增加，体积密度略有升高但变化幅度不大；热震稳定性随Al₂O₃含量的增加而不断提高；4、材料基质部分结构致密，气孔少且多呈封闭的圆孔状。基质中主晶相仍为方镁石，次晶相为尖晶石固溶体、钛酸钙和少量的镁橄榄石。 采用静态坩埚法研究了试样抗炉外精炼渣的侵蚀性能，着重分析了炉渣对镁铝钛耐火材料的侵蚀机理。结果表明：1、镁铝钛耐火材料抗炉外精炼渣性能接近于镁铬耐火材料，但含Cr₂O₃的镁铝钛耐火材料抗渣性能优于不含Cr₂O₃的镁铝钛耐火材料；2、在所研究的范围内，随着试样中TiO₂、Al₂O₃含量的增加，试样的抗渣性能提高；3、炉渣对镁铝钛耐火材料、镁铝铬钛耐火材料的侵蚀主要表现为渗透。在渗透过程中炉渣中的CaO、SiO₂和镁铝钛耐火材料中的方镁石发生反应，使方镁石溶解于CaO-SiO₂-Al₂O₃-MgO系炉渣中形成低熔点硅酸盐相，并与材料中的结合相钛酸钙一起共熔并进一步向砖中渗透。更多还原

【Abstract】 The phase constitutions of magnesia-alumina-titania refractories were designed by the analysis of phase digrams and thermodynamic calculation, by which the the periclase and spinel solid solution (MgAl2O4-Mg2TiO4) were designed as the main crystalline phases, and the calcium titanate and forsterite with high melting point as the bonding phases.The properties and microstructure of magnesia-alumina-titania refractories were studied by means of experiment measurement and the microstrcuture analysis of SEM and EDAX. The influences of sintering temperature, titania content, alumina content on the properties and microstructure of magnesia-alumina-titania refractories were discussed. The results shows that: 1, The apparent porosity decreases and the bulk density increases with the increasing of sintering temperature.2, The apparent porosity decreases, the bulk density and the thermal shock resistance increases with the increasing of titania content. 3, With the increasing of alumina content, the bulk density generally increases, but the thermal shock resistance continuously increases. 4, The refractories have dense matrix and a little amount of pores. The main crystalline phases in the matrix are also the periclase and spinel solid solution, which are bonded by calcium titanate and forsterite with high melting point.The corrosions of the secondary steel refining slags on the refractories were studied by the method of stationary crucible, through which the corrosion mechanisms were discussed by the methods of measuring corroded area and microstructure analysis. The results shows that: l,The slag corrosion resistance of magnesia-alumina-titania refractories is comparable to that of magnesia-chromite refractories. But the slag resistance of magnesia-alumina-chromite-titanla refractories is prior to that of magnesia-alumina-titania refractories. 2, In the ranges involved, the slag corrosionresistance increases with the increasing of titania and alumina content. 3, The penetration of slags into the refractories is the main facts observed. The reaction of slags with the periclase of magnesia-alumina-titania refractories, results in the dissolving of periclase in the CaO-SiO2-Al2O3-MgO slags, and the penetration of slags into the refractories is enhanced by the formation of low melting silicates.更多还原