低介电损耗AlN陶瓷及BN—AlN基陶瓷材料研究

首先利用化学工艺制备出烧结助剂Y2O3均匀混合的AlN粉体及BN均匀包覆AlN的复合粉体。利用无压烧结制备出AlN陶瓷及BN—AlN基复相陶瓷。通过对陶瓷显微结构、热性能及微波介电性能的研究发现，通过化学工艺，将BN包覆到AlN粉体表面，制备出显微结构均匀的AlN-20％BN（质量比）复相陶，其热导率为78．1w／m·K，在Ka波段介电常数为7．2、介电损耗最小值为13×10^-4通过材料化学工艺，将烧结助剂Y2O3均匀添加到AlN基体中，制备出热导率为154．2w／m·K，在Ka波段介电常数为8．5、介电损耗最小值为9．3×10^-4的AlN陶瓷材料。

Preparation of Low Loss Tangent AlN Ceramics and BN-AlN Composites

The low loss tangent AIN ceramics, which have a high thermal conductivity （154.2 W/m · K） and low loss tangent （9.3× 10^-4） at Ka frequency bands, and BN-AlN composites, which have a high thermal conductivity （78.1 W/m · K） and low loss tangent （13× 10^-4） at Ka frequency bands, have been successfully fabricated. First, AIN powders mixed homogeneous with the sintering additive Y2O3 and AIN powders coated homogeneous with BN were prepared via a chemical processing. Next, the green bodies were sintered at pressureless sintering.