New unidirectioally solidified eutectic composites such as AL sub 2O sub 3/Er sub 3Al sub 5 O sub 12 or Al sub 2 O sub 3/GDAlO sub 3 has recently been fabricated by unidirectional solidification. The eutectic ocmposite has a new microstructure, in which ocntinuous networks of Al sub 2O sub 3 phases and oxide ocmpounds interpenetrate without grain boundaries. The eutectic ocmposite fabricatedis thermally stable and has the folllowing properties: in case of Al sub 2O sub 3/Er sub 3Al sub 5O sub 12 ocmposite, (1) the flexural strength at room temperature can be maintained up to 2073K the compressive flow stress at 1873K nad a strain rate of 10 sup -4/sec is about 7 times higher than that of sintered composites of the same ocmposition. (3) it shows neither weight gain or grain growth, even upon heating at 1973 k in an air atmosphere for 500 hours. (4) it shows substantial plastic deformation at 1873 K with a flexural yield stress ofabout 690 MPa and it is found that the plastic deformantio noccurredby dislocation motion in each phaes.
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机译：最近已经通过单向凝固制备了新的单向凝固的共晶复合物，例如AL sub 2O sub 3 / Er sub 3Al sub 5 O sub 12或Al sub 2 O sub 3 / GDAlO sub 3。共晶复合物具有新的微观结构，其中Al sub 2O sub 3相的相通网络和氧化物封端相互渗透而没有晶界。共晶复合材料是热稳定的，并具有以下特性：在Al sub 2O sub 3 / Er sub 3Al sub 5O sub 12复合材料的情况下，（1）室温下的弯曲强度可保持至2073K，在1873K的应变速率为10 sup -4 / sec，大约是相同位置的烧结复合材料的应变速率的7倍。 （3）即使在空气气氛中以1973 k加热500小时，也没有显示出增重或晶粒长大。 （4）在1873 K处表现出明显的塑性变形，弯曲屈服应力约为690 MPa，并且发现在每个阶段中位错运动都不会引起塑性变形。
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