低温烧结AlN陶瓷的微结构和热导率  

Microstructure and Thermal Conductivity of AlN Ceramics Sintered at a Low Temperature

作　　者：乔梁[1] 周和平[1] 王少洪[1] 

机构地区：[1]清华大学材料系新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《材料工程》2003年第2期23-26,共4页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目 ( 5 9995 5 2 3 )

摘　　要：采用CaF2,Y2O3和Li2CO3做添加剂,在低温下制备了高热导率的AlN陶瓷,通过SEM,TEM和XRD研究了AlN陶瓷在烧结过程中微结构及晶格常数的变化及其对热导率的影响。研究发现,当使用CaF2和CaF2-Y2O3做添加剂时,液相对晶粒浸润性较差,不利于AlN晶格的纯化。而添加Li2O-CaF2-Y2O3的AlN陶瓷在烧结温度之前已经完成了液相的重新分布,液相与AlN晶粒之间有较好的浸润性,这促进了AlN陶瓷的致密化和AlN晶格的纯化,有利于获得较高的热导率。Using Li2CO3, CaF2 and Y2O3 as additives, AlN ceramics with high thermal conductivity were achieved at a low sintering temperature The changes occurring on the microstructure and lattice parameters of the sintered AlN ceramics were studied using SEM, TEM and XRD Furthermore, their effects on the thermal conductivity were discussed The results show that the liquid formed in the sintering has a less wetting to the AlN grains, which has no significant benefit to purify the AlN lattice using CaF2 and Y2O3 as additives In AlN ceramics adding Li2CO3CaF2Y2O3, the liquid phase redistributed before the sintering temperature has a good wettability to the AlN grains This promotes the densification of AlN ceramics and the purification of AlN lattice, thus ensuring the high thermal conductivity

关 键 词：低温烧结 ALN陶瓷 氧化铝 微结构 热导率 

分 类 号：TQ174.758[化学工程—陶瓷工业] TQ174.1[化学工程—硅酸盐工业]