易面各向异性羰基铁@SiO_(2)/聚氨酯复合材料吸波性能及其吸收机制

Microwave absorption properties and absorption mechanism of easy-plane anisotropic carbonyl iron@SiO_(2)/polyurethane composites

为了在低频段实现薄层高效微波吸收,首先通过机械球磨技术制备了具有易面各向异性的羰基铁粉;其次通过表面改性在羰基铁粉表面沉积了一层纳米SiO_(2);并通扫描电子显微镜、透射电子显微镜、振动样品磁强计、X射线衍射仪以及矢量网络分析仪对其进行测试表征。实验结果表明,易面各向异性羰基铁@SiO_(2)/聚氨酯复合材料不仅在垂直入射条件下具有优异的吸波性能,同时在斜入射条件下也具有优异的吸波性能;在垂直入射条件下,其反射损耗峰在S波段达到了−43 dB,意味着99.99%的电磁波被高效吸收;在入射角度为60°、厚度为1.5 mm时,在5~15 GHz范围内均能获得有效吸波,真正实现了薄层、宽带、宽角度高效吸收,对于解决先进武器装备急需的高效雷达吸波涂层展现了强大的应用潜力。

To meet impedance matching at low frequencies and obtain high microwave absorption performance,easy-plane anisotropy carbonyl iron powders coated with SiO_(2) were produced by a ball milling technique and a chemical deposition method. Then, a scanning electron microscope, a transmission electron microscope, an X-ray diffractometer, a vibrating sample magnetometer, and a vector network analyzer were used to characterize the samples. The experimental results show that the anisotropic carbonyl iron@SiO_(2)/polyurethane composite has excellent absorbing properties not only at vertical incidence but also at oblique incidence. Under the condition of vertical incidence, its reflection loss peak reaches-43 dB in S-band, which means that 99.99 % of the electromagnetic wave is absorbed efficiently;when the incident angle is 60° and the thickness is 1.5 mm, the effective absorption can be obtained in the range of 5-15 GHz,which truly realizes the efficient absorption of thin layer, wide band and wide Angle, showing a strong application potential for solving the urgent need of efficient radar absorbing coating for advanced weapons and equipment.