高温下金属铝复合氧化镁系耐火材料的相变化

摘要

This work aims at investigating the influence of aluminum on magnesia refractories at high temper-atures.Al-MgO composite refractories were prepared using fused magnesia powder (≤74μm)and alumi-num powder (≤74 μm)as starting materials,and thermoset resin as the binder,firing at 660,1 150,1 350, and 1 550 ℃,respectively.The influence of hot treatment temperature on the phase composition and micro-structure of the refractories was investigated.Results show that MgAl2 O4 appears at 1 150 ℃;as the tem-perature rises to 1 350 ℃,MgAl2 O4 increases and the specimen becomes denser;while as the temperature rises to 1 550 ℃,MgO losses greatly resulting in a huge decrease in densification;besides the spinel phase,there are also some oxynitride fibres and particles formed in the system,which could reinforce the refractories and enhance the mechanical property further.%为研究高温下金属铝对氧化镁系耐火材料的影响，以电熔镁砂细粉（≤74μm）和金属铝粉（≤74μm）为原料，热固性树脂为结合剂，研究了不同温度热处理后（660、1150、1350和1550℃）材料的相组成及显微形貌。结果表明：1150℃时开始反应生成镁铝尖晶石；温度升至1350℃时镁铝尖晶石生成量增多，试样更加致密；温度达到1550℃时氧化镁大量流失，导致试样致密度大幅度下降。体系中除了生成镁铝尖晶石作为结合相外，还生成了少量氧氮化物纤维和颗粒，这些纤维和颗粒作为增强相能够进一步提升材料的力学性能。