(YCa)F_3助烧AIN陶瓷的显微结构和热导率

Microstructure and Thermal Conductivity of Aluminium Nitride with (YCa)F_3 as Sintering Aid

采用（ＣａＹ）Ｆ_３为助烧结剂，低温烧结（１６５０℃， ６ｈ）制备出热导率为２０８Ｗ／ｍ·Ｋ的ＡＩＮ陶瓷，在烧结过程中，热导率随保温时间的变化服从方程：λ（ｔ）＝λ∞－△λ（０）·ｅ^（－ｔ／ｒ）·用ＳＥＭ、 ＳＴｈＭ、 ＴＥＭ和 ＨＲＥＭ对 ＡＩＮ陶瓷的显微结构及其对热导率的影响进行了研究，结果表明，晶粒尺寸对ＡＩＮ陶瓷热导率的影响可以忽略，而分隔在ＡＩＮ晶粒之间的晶界相会降低热导率。

Aluminium nitride ceramics were successfully fabricated through low-temperature sintering by using (YCa)F_3 as the sintering aid. AIN ceramics with a high thermal conductivity of 208W/m·K were obtained after the specimen was sintered at 1650℃ for 6h. Calculation based on the present and reported results led to an equation which describes the dependence of thermal conductivity of AIN on the soaking time in sintering: λ(t) =λ∞ -△λ(0)·e^(t/r). SEM, TEM, SThM and HREM were employed to study, the microstructure-property relationship of AIN ceramics. It was concluded that AIN grain sizes have little effect on the thermal conductivity, while grain boundary phases deteriorate thermal conductivity.