三维织物石膏基微波吸收材料的制备及性能

Preparation and Properties of 3D Fabric-Gypsum Based Microwave Absorbing Materials

采用浸渍工艺在三维织物表面包覆炭黑,并将其与石膏复合制备石膏基微波吸收材料。利用弓形反射法测试了该复合材料在2~18GHz内的吸波性能,结果表明吸波性能随炭黑含量的增加而增强,三维织物的最佳厚度为6mm。三维织物厚度为6mm、乙炔炭黑含量为24%的复合材料在2~18GHz内对电磁波的反射损耗均低于-5dB,最低反射损耗可达-28.3dB。三维织物的特殊结构不仅能够有效改善材料的阻抗匹配,还能够增加材料的电磁波损耗路径,从而达到增强损耗能力、拓宽吸波频宽的目的。此外,三维织物还能够明显增强石膏基材料的抗折性能。

Gypsum-based microwave absorbing materials were prepared by introducing 3D fabrics,which were coated with carbon black(CB)by impregnation technology,and the absorbing properties of the composites were tested by NRL-arc method in 2-18 GHz frequency range.The results indicate that the reflection loss of the composites increases with the increase of CB content,and the optimum thickness of 3D fabric is 6 mm.When the thickness of 3D fabric is 6 mm and the CB content is 24%,the reflection loss of the composites is less than-5 dB in the whole frequency range of 2-18 GHz,and the lowest reflection loss reaches-28.3 dB.The special structure of 3D fabric can not only improve impedance matching condition,but also provid more wave attenuation path,resulting in the high absorption capacity and wide bandwidth.Moreover,the flexural strength of gypsum composites can be increased by 3D fabrics.