TiO_2添加剂对AlN-SiC材料微波衰减性能的影响

Effect of TiO_2 on Microwave Attenuation Characteristics of AlN-SiC Composites

在AlN-SiC复相材料中加入TiO2,采用热压工艺,制备了性能优异的AlN-SiC-TiO2复相微波衰减材料。通过矢量网络分析仪、SEM等测试手段,研究了AlN-SiC复相材料微波衰减性能与SiC含量的之间的关系,以及添加剂TiO2对AlN-SiC复相材料微波衰减特性和显微结构的影响。结果表明,SiC是良好的宽频微波衰减剂,对衰减频谱曲线特征起决定作用;TiO2的添加大大促进了AlN-SiC复相材料的烧结性能和微波衰减性能,添加了TiO2后6 GHz下衰减量由0.6 dB增加到0.85 dB。初步探讨了AlN-SiC-TiO2复相材料的微波衰减机理,电导损耗、介质损耗是其主要的微波衰减机理。

AlN-SiC-TiO2 composites with excellent microwave attenuation characteristics were prepared by hot-pressing under the reasonable controls of sintering temperature and soaking time. The relation between the characteristic of AlN-SiC-TiO2 composites and the SiC content and the effect of TiO2 on the microwave attenuation characteristics and the microstructure of AlN-SiC composites were investigated by network analyzer and SEM etc. The results show that SiC is an excellent wide-frequency microwave attenuant, which determine the characteristic of attenuation curve. TiO2 can greatly improve sintering and microwave attenuation characteristics of AlN-SiC composites. The composites attenuation rises from 0.6dB to 0.85dB when frequency equals 6GHz. The attenuate mechanism of AlN-SiC-TiO2 was analyzed, the main mechanisms of microwave attenuation are probable to the electric conductive loss and the dielectric loss.