Mo／AlN金属陶瓷微波吸收材料的制备与性能表征  

Preparation and characterization of Mo/AlN cermet microwave-absorbing materials

作　　者：程继贵[1] 梁槟星[1] 董洁[1] 蔡艳波[1] 顾瑞[1] 夏永红[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《功能材料》2007年第A08期3041-3044,共4页Journal of Functional Materials

基　　金：国家特种显示工程中心基金资助项目（042301D2）

摘　　要：以Mo与AlN为原料，复合氧化物为烧结助剂，通过常规的成形烧结工艺制备出了Mo含量为30％~40％（质量分数）的Mo／AlN金属陶瓷烧结体。对烧结体的微观结构进行观测，并对其导热系数及力学性能等进行了测试分析，采用矢量网络分析仪对其反射衰减率进行测量，并与纯AlN材料进行了对比。结果表明：通过采用适当的烧结助剂，在1750℃下无压烧结，可以获得相对密度高于98％的Mo／AlN金属陶瓷复合材料烧结体。该烧结体的抗弯强度与导热系数随着Mo含量的增加而提高，含40％Mo（质量分数）试样的抗弯强度和导热系数分别为531．4MPa和156．1W／m．K：不同Mo含量Mo／AlN试样在不同的频段内出现宽频吸收，其中含40％Mo（质量分数）的试样在14～18GHz频率内呈现较宽的吸收频段，最大反射衰减量为-22dB。Mo/AlN cermets with 30%-40 wt% Mo were manufactured by conventional pressing-sintering process using Mo and AIN as starting powder, and composite oxides as sintering aids. The microstructure of the sintered Mo/AlN cermets was observed by scanning micro scope （SEM）. The thermal and mechanical properties, as well as the microwave-absorbing behaviors were also tested. The results showed that Mo/AlN cermets with relative density of more than 98% of the theoretical can be obtained by sintering the compacts at 1750℃ for 2.5h. The bending strength and thermal conductivity of the sintered Mo/AlN cermets increase as Mo content increases. The bending strength and thermal conductivity are 531.4 MPa and 156. 1 W/m-K, respectively, for Mo/AlN cermets with 40 wt% Mo. The introduction of Mo can also improve the microwave-absorbing behaviors of AlN ceramics and the Mo content also has an obvious influence on the microwave-absorbing behaviors of the Mo/AlN cermets. The Mo/AlN samples with 40 wt% Mo have a wider frequency absorbing band in 14~ 18GHz. A maximum reflection loss of --22dB was obtained.

关 键 词：Mo/AlN金属陶瓷吸波材料 无压烧结 反射衰减量 导热系数 抗弯强度 

分 类 号：TQ174.75[化学工程—陶瓷工业]