摘要
采用添加成孔剂和冰冻–干燥法制备具有不同气孔率(30%～60%)的多孔Si3N4陶瓷,研究了不同制备工艺对多孔Si3N4陶瓷介电性能的影响。结果表明:不同的成型工艺制备出具有不同孔分布的氮化硅多孔陶瓷,添加成孔剂制备的多孔陶瓷具有较大的孔,洞分布在致密的基体上;冰冻–干燥法制备的多孔陶瓷具有复合孔分布。对样品的介电特性的研究表明,随着样品的气孔率增加,其介电常数和介电损耗减小;添加成孔剂制备样品的介电常数小于冰冻–干燥法制备样品,而其介电损耗较大,多孔Si3N4陶瓷的介电常数和介电损耗分别在5.21～2.91和9.6×10–3～2.92×10–3范围内变化。
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 microstructures 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 fabrication 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 flat shape scattered almost uniformly in the Si3N4 matrix. The porosity, pore structure and dielectric properties were measured separately. 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.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2009年第8期1443-1446,共4页
Journal of The Chinese Ceramic Society
基金
陕西科技大学科研启动基金BJ08–02资助项目
关键词
多孔氮化硅陶瓷
成孔剂
冰冻-干燥
介电性能
porous silicon nitride
pore-forming agent
freeze-drying
dielectric properties
