硅酸盐学报2009，Vol.37Issue(8)：1443-1446,4.
制备工艺对多孔Si3N4陶瓷介电性能的影响
INFLUENCES OF FABRICATION PROCESS ON DIELECTRIC PROPERTIES OF POROUS SILICON NITRIDE CERAMICS
摘要
Abstract
Two different series of porous silicon nitride (Si3N4) ceramics with different porosities from 30% to 60% were fabricated using two different preparation routes: the addition of pore-forming agent and freeze--drying. The microstruetures of the samples were observed in detail. The results show that there is a big difference in the porous structure of the samples prepared by the different fab-rication routes. The samples prepared using the pore-forming agent have a dense matrix containing close pores and cavities with some needle-shaped and flaky β-Si3N4 grains, while those prepared by the freeze-drying process contain open and connective pores with a fiat shape scattered almost uniformly in the Si3N4 matrix. The porosity, pore structure and dielectric properties were measured sepa-rately. The results show that with the increase of porosity, the electric constant and dielectric loss of the ceramic decrease, and the pore distribution of the ceramic is also a major factor that influences its dielectric properties. The ε of the samples prepared by the addition of pore-forming agent is lower than that by freeze-drying, while its tan δ is higher under the same porosity. The ε and tan δ of the porous Si3N4 ceramics typically are in the range of 5.21-2.91 and 9.6×10-3?-2.92×10-3, respectively.关键词
多孔氮化硅陶瓷/成孔剂/冰冻-干燥/介电性能Key words
porous silicon nitride/pore-forming agent/freeze-drying/dielectric properties分类
化学化工引用本文复制引用
李军奇,周万城,罗发,朱振峰,马建中..制备工艺对多孔Si3N4陶瓷介电性能的影响[J].硅酸盐学报,2009,37(8):1443-1446,4.基金项目
陕西科技大学科研启动基金(BJ08-02)资助项目. （BJ08-02）
