Fe/Al_2O_3/石蜡复合材料的制备及微波吸收性能研究

为了改善Fe粉的微波吸收性能,采用sol-gel法与H_2还原法制备了w(Al_2O_3)为0.5%~5.0%的Fe/Al_2O_3复合粉。利用SEM和激光粒度分析仪分析了所制粉末的形貌与粒度分布;并将所制复合粉末与石蜡按质量比80:20制成Fe/Al_2O_3/石蜡复合材料,研究w(Al_2O_3)对复合材料微波吸收性能的影响。结果表明:Fe/Al_2O_3复合粉的外形呈片状与针状,其粒度分布很宽。当w(Al_2O_3)由0增加到5.0%时,复合材料的复介电常数实部ε′从11增加至21;复磁导率虚部μ″呈多模共振的曲线形式;w(Al_2O_3)为2.0%,厚为2mm的Fe/Al_2O_3/石蜡复合材料的–5dB反射损失R频宽为4.6GHz。

Preparation and microwave absorbing properties of Fe/Al2O3/wax composite materials

To improve the microwave absorbing property of Fe powder, Fe/Al2O3 compound powder containing 0.5%~5.0% (mass fraction) of Al2O3 was prepared by the sol-gel method and H2 reduction method, respectively. The morphology and particle size distribution of the prepared powder were characterized with SEM and laser particle size analyzer. The Fe/Al2O3/wax composite materials were fabricated from prepared Fe/Al2O3 compound powder and wax at a mass ratio of 80:20. The effect of w(Al2O3) doped on the microwave absorbing property of obtained Fe/Al2O3/wax composite materials was also investigated. The results indicate that the appearance of the Fe/Al2O3 compound powder shows flake-like and needle-like shape with a wide particle size distribution. The real parts of complex permittivity ε′for the composite materials increase from 11 to 21 as w(Al2O3) increases from 0 to 5.0%; their imaginary parts μ″of complex permeability exhibit several slightly damped ferromagnetic resonances. The bandwidth in reflection loss of–5dB for Fe/Al2O3/wax composite materials with 2.0%(mass fraction) of Al2O3 and 2mm thickness is 4.6GHz.