SiO_2-SiC基复合材料吸波性能的研究

Synthesis and Microwave-Absorption Properties of SiO_2-SiC Matrix Composites

首先利用溶胶-凝胶法制备SiO2-SiC复合粉体,采用SEM、XRD、DSC-TG等技术对复合粉体进行表征。结果表明,溶胶-凝胶法能够制备具有核-壳结构SiO2-SiC复合粉体。再将SiO2-SiC复合粉体与BaTiO3、Fe3O4以及环氧树脂以不同比例进行混合固化制得吸波材料样品,采用矢量网络分析仪测量样品的反射率。结果表明,SiO2-SiC复合粉体具有一定的吸波效果,20%含量的SiO2-SiC复合粉体样品在18GHz时反射率达–2.07dB,BaTiO3、Fe3O4的加入实现复合吸波效果,当SiO2-SiC:BaTiO3:Fe3O4=6:2:2(体积分数,下同)时,在5.75GHz时反射率达到–13.97dB,合格带宽为10.08GHz。

SiO2-SiC composite particles were prepared by using a sol-gel process. The techniques of SEM, XRD and DSC-TG were used to characterize the phase and microstructure of the as-obtained SiO2-SiC particles. The results show that a core-shell structure was constructed in the composite particles with the core of SiC and the shell of amorphous SiO2. The microwave absorbents were blended and solidified with epoxide resin, SiO2-SiC composite particles, BaTiO3 and Fe3O4 powders with various ratios. The vector network analyzer was used to measure the reflectivity of the SiO2-SiC matrix composites, the result shows that SiO2-SiC composite particles could absorb microwave, the reflectivity of the sample with 20 wt% SiO2-SiC particles is -2.07 dB at 18 GHz, adding BaTiO3 and Fe3O4 powders, the reflectivity of composite absorbents could be -13.97 dB at 5.75 GHz while eligible frequency range is 10.08 GHz.