Abstract: In order to investigate the effect of the solid solution reaction between corundum and magnesium aluminate spinel on the properties and microstructure of MA-Al₂O₃ materials,two groups of MA-Al₂O₃ materials were prepared using fused magnesium aluminate spinel as the main raw material,adding a small amount of sintered corundum fine powder to partially replace spinel fine powder,or using white corundum as the main raw material and adding a small amount of fused magnesium aluminate spinel fine powder to replace white corundum fine powder.The results show that:(1)the solid solution reaction occurs in both groups,increasing the alumina content in the magnesium aluminate spinel from about 76 mass% to over 80 mass%,thereby strengthening the bonding between the aggregates and matrix of the samples,reducing structural defects,and improving the hot performance of the materials;(2)for the MA-Al₂O₃ specimens with magnesium aluminate spinel as the main raw material,adding corundum increases the cold compressive strength and improves the hot creep resistance and thermal shock resistance;(3)for the MA-Al₂O₃ specimens with corundum as the main raw material,adding magnesium aluminate spinel fine powder significantly improves the cold compressive strength,hot creep resistance and hot modulus of rupture.

Key words: solid solution reaction, magnesium aluminate spinel, corundum, physical properties

摘要： 以电熔镁铝尖晶石为主要原料并加入少量烧结刚玉细粉部分替代尖晶石细粉,或以白刚玉为主要原料并加入少量电熔镁铝尖晶石细粉替代白刚玉细粉,制备了两组MA-Al₂O₃材料。研究刚玉与镁铝尖晶石之间的固溶反应对材料性能及显微结构的影响。结果表明:1)在两组材料中均发生了固溶反应,使得镁铝尖晶石的富铝程度增大,镁铝尖晶石中的氧化铝含量(w)由约76%增加到80%以上,从而加强了试样骨料与基质的结合,减少结构缺陷,改善了材料的高温性能;2)在以镁铝尖晶石为主要原料的MA-Al₂O₃材料中,加入烧结刚玉可使其常温耐压强度增大,改善其高温抗蠕变性和抗热震性;3)在以白刚玉为主要原料的MA-Al₂O₃材料中,加入镁铝尖晶石细粉,其常温耐压强度、高温抗蠕变性和高温抗折强度均有大幅度提高。

关键词: 固溶反应, 镁铝尖晶石, 刚玉, 物理性能