毕业设计（论文）-液相包覆法引入B2O3对Ba2Ti9020陶瓷性能的影响.doc

液相包覆法引入B2O3对Ba2Ti9020陶瓷性能的影响
摘要
近年来,因其具有优异的微波介电性能Ba2Ti9O20受到了广泛关注。Ba2Ti9O20作为滤波器、谐振器等核心微波元件已广泛应用于现代移动通信、卫星广播、无线电遥控等领域。多层陶瓷共烧技术要求微波介质陶瓷与高导电率且相对廉价的Ag和Cu共烧。故降低Ba2Ti9O20的烧结温度到Ag和Cu的熔点温度以下以满足共烧的需求是今后的发展方向。
本文以BaCO3和TiO2粉末为原料,采用固相反应合成Ba2Ti9O20主晶相,通过液相包覆法引入B2O3助烧剂以期降低其烧结温度,结合XRD、SEM分析,研究了前驱溶液浓度对包覆B2O3的Ba2Ti9O20陶瓷物相组成、显微结构和介电性能的影响规律。结果表明,通过液相包覆B2O3可以将Ba2Ti9O20陶瓷的烧结温度从1400℃降至1250℃,%。 H3BO3的Ba2Ti9O20陶瓷在1MHz下测试的介电性能为:εr=42,tanδ=,=-4ppm/℃。与1400℃下烧结纯的Ba2Ti9O20陶瓷相比,基本保持了原有介电性能。
关键词:微波介质陶瓷,助烧,介电性能,液相烧结,液相包覆
Influence of Aiding in B2O3 by Liquid Coating
B203 on Ba2Ti9O20 Ceramics
ABSTRACT
Recently,Ba2Ti9O20 is widely studied due to its good dielectric properties. Ba2Ti9O20 is widely used as the core ponents in modern munications, satellites broadcasting and radio-controlled fields, for example, in filters and resonators. Multi co-firing requires that dielectric ceramics be co-fired with internal conductors such as Ag and Cu. Therefore, it is important to lower the sintering temperatures of Ba2Ti9O20 to less than the melting points of Ag or Cu without deteriorating the microwave dielectric properties.
Ba2Ti9O20 main phase are prepared from BaCO3 and TiO2 powders. In order to reduce the sintering temperature of Ba2Ti9O20 ceramic we have used liquid coating technology to dope B2O3. The position and crystalline structure of Ba2Ti9O20 is tested by XRD and SEM .The results show that liquid coating with B2O3could decrease the sintering temperature of Ba2Ti9O20ceramics efficiently from 1400°C to 1250°C. A high relative density of % and good dielectric properties of εr=42,tanδ= (1 MHz)=-4ppm/℃were obtained for the B203-added Ba2Ti9O20 ceramics sintered at 1250°C for pared with Ba2Ti9O20 that sintered at 1400°C it's remained has good dielectric properties.
KEY WORDS: microwave dielectric ceramics, sintering aid, dielectric property, liquid phase sintering; liquid coating
目录
第一章绪论 1
§ 微波介质陶瓷的发展 1
§ 微波的应用频段 2
§ 微波介质陶瓷的分类 3
§