将w( Al2O3)为71％、78％和85％的3种不同组成的镁铝尖晶石细粉(粒度均≤0.074 mm)分别与α-Al2O3微粉混合,采用半干法压制成φ50 mm × 50 mm的MA - Al2O3质试样,干燥后,分别在1300 ～1650℃保温4h煅烧,随炉冷却后测量试样煅烧后的线变化率、显气孔率、体积密度和物相组成.结果表明:镁铝尖晶石原料的富铝程度越高,MA-Al2O3材料的可烧结性越差,其二次尖晶石化反应需在更高的温度区间完成,反应伴随的膨胀效应对MA-Al2O3材料烧结的限制作用也更为突出.%The MA-AI2O3 specimens with the size of ?50 mm ×50 mm were prepared by mixing the fines of magnesium aluminate spinel (the mass percent of AI2O3 was 71% ,78% ,and 85%, respectively; grain size ≤ 0.074 mm) and micropower of α-AI2O3, semi-dry pressing, drying, firing at different temperatures for 4 h (1 300-1 650 ℃),and cooling. The linear change rate, apparent porosity, bulk density and phase compositions were determined. The results show that the higher aluminum-rich degree of magnesium aluminate decreases the sinterability of MA-AI2O3 specimens, the secondary spinelization reaction need to complete at higher temperatures, and the occurred expansion effect plays more obvious hindering role in MA-AI2O3 materials sintering.
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