孔结构对氮化硅陶瓷介电性能的影响  

Effect of Porous Structure on the Dielectric Properties of Silicon Nitride Ceramics

作　　者：李军奇[1] 赵锴[1] 徐洁[1] 罗发[1] 朱冬梅[1] 周万城[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2007年第A01期557-559,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目(90305016)

摘　　要：采用添加成孔剂和冰冻-干燥法制备了具有不同气孔率的氮化硅多孔陶瓷,研究了该陶瓷在9.3GHz的微波介电性能。用SEM对微观形貌进行观察。结果表明,不同的成型工艺制备出具有不用孔结构的氮化硅多孔陶瓷,添加成孔剂制备的多孔陶瓷为较大的孔、洞分布在较致密的基体上;冰冻-干燥法制备的多孔陶瓷具有复合孔结构。对试样介电特性的研究表明,除了气孔率对介电常数和介电损耗有较大影响外,孔结构也是影响其介电特性的重要因素。Two different series of porous silicon nitride ceramics, whose volume fractions of porosity are from 0 to 0.6, were fabricated using two different preparation routes： （i） the addition of pore-forming agent, and （ii） freeze-drying processing. Effects of the amount of pore-forming agent and the concentration of water-based slurry on porosity were investigated. In order to predict and understand experimental dielectric properties-porosity relationships, porosity, porous structure and dielectric properties were evaluated separately for each series of materials. The results showed that besides the volume fraction porosity, the geometrical nature was also a major factor that influences the dielectric properties of the samples.

关 键 词：氮化硅 多孔陶瓷 成孔剂 冰冻 干燥法 介电性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]