热处理对AlN陶瓷的热导率及介电性能的影响

Effect of Heat Treatment on Thermal Conductivity and Dielectric Properties of AlN Ceramics

采用放电等离子烧结技术制备Al N陶瓷,并利用真空无压烧结方法进行热处理。研究了不同烧结助剂在高温热处理过程中对Al N陶瓷的物相组成、显微结构、导热性能及介电性能的影响。结果表明,Al N陶瓷经过热处理后,Al N晶粒进一步发育长大,尽可能实现面接触,材料中的晶间相分布更加合理。与只引入单一稀土氧化物为烧结助剂的Al N陶瓷相比,引入复合烧结助剂稀土氧化物及氟化钙(Ca F2)的Al N陶瓷经过热处理后,在有效除氧及生成具有挥发性晶间相双重效果作用下,材料热导率及介电损耗改善效果明显。

Aluminum nitride （ALN） ceramics prepared by a fast spark plasma sintering method were heat-treated by a vacuum pressureless sintering method. Effect of sintering additive on the phase composition, microstructure, thermal and dielectric properties of ALN ceramics during high-temperature heat treatment process was investigated. The results show that the heat treatment enhances the growth of AIN grains and the distribution of secondary phases. Compared to AIN ceramics with single rare earth oxide, the thermal conductivity and dielectric loss of ALN ceramics with earth oxide-CaF2 multiple sintering additive are improved due to the effects of effective removing oxygen and forming evaporable secondary phases.