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以氮化铝、金属Mo为原料,Y2O3为烧结助剂,氮气氛下、1800~1900℃热压烧结制备Mo/AlN复相材料。利用XRD、SEM对材料的相组成、显微结构进行表征,四探针法测试复相材料的电阻率,微带线法测试2~20 GHz频率范围内材料的微波衰减特性,探讨了渗流现象与衰减特性之间的内在联系。结果表明:当Mo添加量为4.56 vol%~15.03 vol%,材料呈现宽频衰减特性,且随着Mo含量和烧结温度的增加衰减量增大;当Mo添加量为16.18 vol%~24.88 vol%,材料仅在6、10、14、18 GHz 4个频率点出现了明显的谐振峰。根据渗流模型对电阻率数据进行拟合,得到导电相渗流阈值Vc和相应电阻率分别为14.87 vol%和11.59Ω.m。当Mo体积分数V>Vc时,复相材料的衰减特性由宽频向选频转变。
Aluminum nitride, metal Mo as raw materials, Y2O3 sintering aids, nitrogen atmosphere, 1800 ~ 1900 ℃ hot pressing sintering Mo / AlN composite material. The phase composition and microstructure of the composites were characterized by XRD and SEM. The four-probe method was used to measure the resistivity of the composite materials. The microstrip line method was used to test the microwave attenuation characteristics of the materials in the frequency range of 2 ~ 20 GHz. The seepage phenomena And attenuation characteristics of the intrinsic link between. The results show that when the Mo content is 4.56 vol% ~ 15.03 vol%, the material exhibits broadband attenuation characteristics, and the attenuation increases with increasing Mo content and sintering temperature. When the Mo content is 16.18 vol% ~ 24.88 vol% The material shows significant resonant peaks at only 4 frequencies of 6, 10, 14 and 18 GHz. The resistivity data were fitted according to the seepage model, and the threshold Vc and corresponding resistivity of the conductive phase were 14.87 vol% and 11.59Ω.m respectively. When the volume fraction of Mo is V> Vc, the attenuation characteristics of the complex phase material change from a wide frequency to a selective frequency.