纳米Y_2O_3对多孔α-Al_2O_3陶瓷的助烧结作用研究

Study on the Sintering-aid Action of Nano Yttrium Oxide on the Porous Alumina Ceramic

采用有机物辅助的溶胶-凝胶法将少量的纳米氧化钇(<2 wt%)均匀地分散在α-Al2O3(平均粒径为40μm)颗粒的表面。采用SEM和万能材料测试仪表征多孔α-Al2O3陶瓷的微观结构和弯折强度,借以表征纳米Y2O3对多孔α-Al2O3陶瓷的助烧结作用。结果显示:纳米氧化钇涂层均匀地分布在α-Al2O3颗粒表面,通过形成液相及化学反应,起到明显地助烧结作用,这种助烧结作用随纳米氧化钇含量的增加而增加。在氧化铝颗粒的颈部,氧化钇嵌入氧化铝颗粒的晶界中,增加了α-Al2O3陶瓷的弯折强度。但由于反应物处于氧化铝晶界处,导致多孔氧化铝的弯折强度并不高,因此,并不适合做多孔氧化铝的助烧结剂。

A small amount of nano yttrium oxides（ 2 wt%） were prepared on the surface of alumina（the mean particle size is 40μm） using polymer aid sol-gel method. The microstructure and then bending strength of the obtained samples were characterized by SEM and universal material tester, which is also used to characterize the sinteringaid of nano yttrium oxides. The results show that the nano yttrium oxides distributed evenly on the surface of alumina. The sintering-aid of nano yttrium oxides is obvious, which processes by the chemical reaction with alumina and the liquid sintering. This sintering-aid increases with the increases of the content of yttrium oxide. In alumina microstructure, the nano yttrium oxides were embedded into the interface of the alumina particles, which increases the bending strengths of the porous ceramic. However, the reaction product remains in the surface of alumina which decreases the bending strength. Finally, the bending strength of the porous alumina ceramic is not high, therefore,nano yttrium oxide is not suit for the sintering-aid of porous alumina ceramic.