Li_2O对低温烧结AlN陶瓷热导率的影响.pdf

第20 卷 第4期 总第80期 Vol 1 20 No 1 4 Materials Science Engineering Dec. 2002 :1004-793X(2002)04-0490-04 Li OAlN 2 , ( ,, 100084) = CaF , Y O Li CO , 1650e 170WPm#K AlN 2 2 3 2 3 , SEM, TEM XRD AlN , , CaF-Y O , , AlN , AlN 2 2 3 Li O AlN , AlN 2 , = ; ; ; :TB321 :A Effect of Li O on the Thermal onductivity of AlN eramics 2 Sintered at Low Temperature QIAOLiang, ZHOU He-ping (State Key Lanboratory of New eramics and Fine Processing, Tsinghua University,Beijing 100084, hina) = Abstract AlN ceramics with the thermal conductivity above 170WPm#K were achieved at the sintering temperature of 1650e by concurrent addition of CaF , Y O and Li CO .The changes occurring on the microstructure and lattice parameters of the sintered AlN ce- 2 2 3 2 3 ramics were studied using SEM,TEM and XRD. Further, their effects on the thermal conductivitieswere 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 in- creasing thermal conductivities during the sintering mainly come from the enhancement of densification. Li O addition improvesthe wettabili- 2 ty of the liquid to the AlN grains, thus promoting the purification of AlN lattice and ensuring the high thermal