摘要
使用CaF2 ,Y2 O3和Li2 CO3做添加剂 ,在 16 5 0℃的低温下制备出热导率高于 170W m·K的AlN陶瓷 ,通过使用SEM ,TEM和XRD研究了AlN陶瓷在烧结过程中微结构与晶格参数的变化 ,并讨论了其对热导率的影响。研究发现 ,当使用CaF2 Y2 O3做添加剂时 ,液相对晶粒浸润性较差 ,不利于AlN晶格的纯化 ,AlN热导率的增加主要来自于致密度的提高。而Li2 O的加入则改善了液相与AlN晶粒的浸润性 ,从而促进了AlN晶格的纯化 。
AlN ceramics with the thermal conductivity above 170W/m\5K were achieved at the sintering temperature of 1650℃ by concurrent addition of CaF\-2,Y\-2O\-3 and Li\-2CO\-3.The changes occurring on the microstructure and lattice parameters of the sintered AlN ceramics were studied using SEM,TEM and XRD.Further,their effects on the thermal conductivities 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.Thus,the increasing thermal conductivities during the sintering mainly come from the enhancement of densification.Li\-2O addition improves the wettability of the liquid to the AlN grains,thus promoting the purification of AlN lattice and ensuring the high thermal conductivity.
出处
《材料科学与工程》
CSCD
北大核心
2002年第4期490-493,498,共5页
Materials Science and Engineering