AlN粉末特性对AlN-BN复合陶瓷致密化的影响

Influence of AIN powder characteristic on densification of AlN-BN composite ceramics

以比表面积分别为4．26和17．4m^2／g两种A1N粉末为原料，添加5％Y2O3作为烧结助剂制备AIN15BN陶瓷（质量分数，％），研究了A1N粉末特性对复合陶瓷致密化过程的影响。结果表明，A1N粉末比表面积对复合陶瓷致密化有重要影响，比表面积高的AIN粉末所制备的复合陶瓷致密化过程主要发生在1500-1650℃，1650℃烧结3h后，复合材料的相对密度达95．6％，继续升高温度，对材料的密度影响不大；而低比表面积的A1N粉末所制备的复合陶瓷的致密化过程主要发生在1650～1850℃，1850℃烧结3h，复合陶瓷的相对密度为86．4％。即高比表面积的AIN粉末有利于获得相对密度高的A1N—BN复合材料。

AIN-15BN （mass fraction, %） composite ceramics were fabricated with two different kinds of A1N powders with specific surface areas of 4.26 m^2/g and a 17.4 m^2/g, respectively, and 5%~ Y2 O2 as sintering additives. The effects of the specific surface area of A1N powders on the densification of AIN-BN composite ceramics were studied. The results show that the specific surface area of A1N powders has great influence on the densification process of composite ceramics. The densification temperature of composite ceramics is at 1500-1650℃ with high specific surface area A1N powder, and A1N-BN ceramics with relative density 95.6% was obtained after sintering at 1650℃ for 3 h. The density of this composite does not increase with the further increasing of sintering temperature. For A1N-BN ceramics prepared with low specific surface area A1N powders, the densification temperature is in the range of 1600-1850℃, and A1N-BN ceramics with relative density 86.4% was obtained after sintering at 1850℃ for 3 h. The high specific surface area of A1N powders can enhance the densification of AINBN composite ceramics.