航空学报 > 2003, Vol. 24 Issue (3): 273-277

用于阻抗变换层的Li2O-Al2O3-SiO2玻璃陶瓷制备及其微波介电特性

罗发, 周万城, 焦桓, 赵东林   

  1. 西北工业大学凝固技术国家重点实验室 陕西西安 710072
  • 收稿日期:2002-04-29 修回日期:2002-06-24 出版日期:2003-06-25 发布日期:2003-06-25

Preparation and Microwave Dielectrical Properties of Li2O-Al2O3-SiO2 Glass-Ceramic Used as an Impedance Transfer Layer of Microwave Absorbing Materials

LUO Fa, ZHOU Wan-cheng, JIAO Huan, ZHAO Dong-lin   

  1. State Key Laboratory of Solidification Processing; Northwestern Polytechnical University; Xi'an 710072; China
  • Received:2002-04-29 Revised:2002-06-24 Online:2003-06-25 Published:2003-06-25

摘要: 采用热压和凝浇注无压烧结的方法制备了Li2O-Al2O3-SiO2 玻璃陶瓷阻抗变换层,研究表明烧结的工艺方法和参数对该玻璃陶瓷的致密度和复介电常数有很大的影响。在较高烧结温度和压力下,该玻璃陶瓷的复介电常数保持不变。降低烧结温度和压力时,能够得到一系列复介电常数在较小范围内变化的Li2O-Al2O3-SiO2 玻璃陶瓷,但复介电常数不随频率发生变化。将该玻璃陶瓷作为吸波材料的阻抗变换层后,大幅度提高了材料的吸波性能,而且其制备工艺对吸波性能也有一定的影响,可以通过改变该玻璃陶瓷的烧结条件来满足不同吸波材料设计对阻抗匹配层的多种要求。

关键词: Li2O-Al2O3-SiO2玻璃陶瓷, 阻抗, 复介电常数, 吸波材料

Abstract: The low thermal expansion coefficient and the moderate permittivity of Li2O-Al2O3-SiO2 glass-ceramicmake it possible to be used as an impedance transfer layer of radar wave absorbing materials to increase the microwave absorbing efficiency and expand absorbing bands. But a series of accurate permittivities of impedance transfer are needed to meet the impedance matching design. Therefore, the relationship between permittivity of the glassceramic and sintering conditions was studied. The results showed that the real and imaginary parts of permittivity ofthe glass-ceramic increase with the sintering densities, and no frequency dependency of permittivity was found. Thereflectivity-frequency curves illustrate that the attachment of the glass-ceramic to the microwave absorbing materialsgreatly reduces the materials’reflectivity to microwave and a little change of permittivity of the glass-ceramic can also exert a remarkable influence on microwave absorbing materials. So an expected permittivity of the glass-ceramic isneeded and can be obtained by varying sintering conditions of the glass-ceramic.

Key words: Li2O-Al2O3-SiO2 glass-ceramic, impedance, permittivity, microwave absorbing material

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