基于铁氧体制备的泡沫吸波材料性能

Properties of Foam Wave Absorbing Materials Prepared Based on Ferrite

为了研究铁氧体的电磁性能以及铁氧体引入量的质量分数和样块厚度对材料性能的影响,以玻璃和陶瓷造粒料为基料,炭黑为发泡剂,引入铁氧体,经过球磨、烧结、发泡、退火工艺后制备出泡沫吸波材料.结果表明:900℃处理对铁氧体的电磁性能无明显影响.铁氧体引入量的质量分数为5%和10%的吸波性能优于铁氧体为15%和20%引入量的吸波性能;研究初步显示,该结果是由于铁氧体的引入影响多孔材料的泡孔结构.铁氧体引入量的质量分数为10%时,材料的吸波性能随着样块厚度的增加而增大;样块厚度为50 mm时,材料的有效吸收带宽(反射率小于-10 d B)达18 GHz,反射率低至-23.4 d B.

To study the electromagnetic properties of the ferrite and the influences of the ferrite addition and the thickness of samples on the properties of the materials,foam wave absorbing materials were fabricated by introducing some ferrite and using glass and ceramic granulated material as base materials and carbon black as vesicant,with the processes of ball milling,sintering,foaming and annealing. The electromagnetic properties of ferrite had no significant change after the heat treatment at 900 ℃. The wave absorbing performance of materials with 5% and 10% ferrite were better than that of the materials with 15% and 20% ferrite contents,which was attributed to the fact that the incorporation of the ferrite influenced the porous structure of foam materials. Moreover,when content of ferrite was 10%,the wave absorption of the material increased with increasing samples＇ thickness. The effective absorption bandwidth（ reflectivity 〈- 10 d B） of 50 mm thick material reached 18 GHz,and its lowest reflectivity was- 23. 4 d B.