Li_20对AlN陶瓷低温烧结的影响  

EFFECT OF Li_2O ON SINTERING OF AIN CERAMICS AT LOW TEMPERATURE

作　　者：乔梁[1] 周和平[1] 陈可新[1] 王少洪[1] 

机构地区：[1]清华大学新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《硅酸盐学报》2002年第6期743-748,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目资助(59995523)。

摘　　要：利用XRD,SEM和TEM研究了Li2O-CaF2-Y2O3体系在/AlN陶瓷低温烧结中的作用机理,研究发现,添加Li2O的/AlN陶瓷有着更低的收缩开始温度和更大的收缩率,这种收缩来自于含Li玻璃相与CaYAlO4液相的共同作用。在烧结过程中,Li2O不仅改变了AlN烧结过程中的相组成,而且改善了液相的性质。由于Li2O和Al2O3在l 100℃以下反应生成含Li玻璃相,使得AlN开始收缩的温度大为降低。在1 600℃以上,含Li玻璃相分解散失,有利于AlN晶界的纯化,同时,CaYAl3O7向CaYAlO4的转变以及液相CaYAlO4在烧结过程中稳定存在,保证了含Li玻璃相散失后AlN的持续收缩。XRD,SEM and TEM were employed to study the mechanism of low temperature sintering of AlN ceramics with Li2O, CaF2 and Y2O3 as additives. The results show that the AlN ceramics containing Li2O have a lower temperature at which AIN begins to shrink and a larger shrinkage at 1 650 ℃ due to the promotion of the glass phase containing Li and liquid CaYAlO4. Li2O not only changed the phase compositions but also improved the properties of the liquid phase in the AlN ceramics during the sintering. The glass phase containing Li formed from the reaction between Li2O and A12O3 below 1 100 ℃ significantly decreased the starting temperature of AIN shrinkage. Above 1 600℃ ,the glass phase containing Li was lost because of the decomposition and evaporation of Li2O, which purifies the grain boundaries of AlN. The transformation from CaYAl3O7 to CaYAlO4, which exists in AlN in liquid form, simultaneously makes the continuous shrinkage possible after Li2O evaporated.

关 键 词：LI2O ALN陶瓷 低温烧结 影响 氮化铝陶瓷 氧化锂 液相 

分 类 号：TQ174.758[化学工程—陶瓷工业]