关键词: 固溶反应, 镁铝尖晶石, 刚玉, 物理性能

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