毕业设计（论文）-添加BCB和ZnO的CLST陶瓷的显微结构精选.doc

添加BCB和ZnO的CLST陶瓷的显微结构 CLST(CaO-Li2O-Sm2O3-TiO2)微波介质陶瓷是一种广泛用作介质谐振器的陶瓷材料，该陶瓷材料的四种成分摩尔比为CaCO3：Li2CO3：Sm2O3：TiO2为16：12：9：63，具有频率温度系数小，介电常数高，品质因数适中等优良性能。本课题用加入BCB和ZnO助烧剂，通过固相反应法制备陶瓷粉体，研究对CaO–Li2O–Sm2O3–TiO2陶瓷低温烧结和介电性能的影响，探索其助烧机理，在获得优良的介电性能的同时，降低CLST陶瓷的烧结温度。同时利用TEM、SEM等分析烧结助剂在微波介质陶瓷中的分布以及陶瓷晶界、晶界附近的晶相、玻璃相、晶相与玻璃相之间反应情况，从而验证低温烧结机理为液相烧结，并且在1000℃烧结3h时，其主晶相为正交钙钛矿相，同时获得了最佳介电性能：εr =.53，tanδ=0.0259，τf = 28ppm / ℃。 微波介质陶瓷，低温烧结，介电性能，BCB，ZnO，液相烧结The microstructure of CLST Ceramics With Addition of BCB and ZnO ABSTRACT CLST(CaO-Li2O-Sm2O3-TiO2) microwave dielectric ceramics are widely used in the medium resonator. The mole ratio of CaCO3: Li2CO3: Sm2O3: TiO2 was 16: 9: 12: 63, it exhibits superior microwave dielectric properties: a high dielectric constant(εr), low loss value(tanδ), and a near zero temperature coefficient of the resonant frequency(τf). We selected the BCB and ZnO as a sintering additive. The CLST ceramics powder synthesized by solid state reaction method, low-temperture sintering and dielectric properties of the CLST microwave dielectric ceramics have been investigated. We probe into sintering mechanism. We can reduce the sintering temperature of CLST ceramic, at the same time,it will obtain excellent dielectric properties. The ceramic grain, grain near the crystal glass, crystal glass phase reaction condition between facies and additives in the distribution of microwave dielectric ceramic were studied by transmission electron microscopy(TEM), scanning electron microscopy(SEM), and precise LCR, respectively. Thus the low-temperature sintering mechanism is liquid sintering. It sintered 3h at 1000℃, its main crystalling phase is orthogonal perovskite phase. It have good dielectric properties ofεr =73.53，tanδ=0.0259，τf = 28ppm / °C。. KEY WORDS: microwave dielectric ceramic, low-temperature sintering, dielectric properties,BCB, ZnO,liquid sintering 目 录 第一章 前 言 1 §1.1 微波介质陶瓷概述 1 §1.1.1 微波介质陶瓷概念 1 §1.1.2 微波介质陶瓷分类及主要性能参数 1 §1.2 微波介质陶瓷的低温烧结 2 §1.2.1 低温烧结的常用方法 2 §1.2.2 常用的助