镍铁合金/铁包云母粉复合吸波涂层材料的频散特性

目的探究不同质量分数配比的镍铁合金/铁包云母粉复合吸波涂层材料的频散特性。方法利用扫描电镜(SEM)观察镍铁合金和铁包云母粉的微观形貌,并使用仪器附带的能谱分析仪对样品所选区域的各元素含量进行测量。用矢量网络分析仪研究了不同质量分数下的镍铁合金/石蜡、铁包云母粉/石蜡同轴样品的介电常数与磁导率。用弓形法测试在2~18 GHz频段内镍铁合金和铁包云母粉以不同质量比加入环氧树脂-聚酰胺体系中制备的不同厚度的单层吸波涂层的反射损耗。结果镍铁合金频散特性较好,对电磁波损耗较大,将其作为吸波涂层的填料,减少吸收剂的用量同时降低了涂层的厚度。铁包云母粉的介电常数的实部较低,与自由空间的阻抗匹配较好,拓宽了吸波频带。镍铁合金和铁包云母粉作为填料,以质量分数30%/30%制备厚度1.2 mm的单层吸波涂层,在2~18 GHz其最小反射值达到了-21.8 d B,小于-10 d B的带宽达到10.5 GHz。结论镍铁合金与铁包云母粉以合适质量比复合,制备的吸波涂层材料厚度薄、吸波频带宽。

Dispersion Properties on Nickalloy/ Iron Package Mica Powder Composite Absorbing Coatings

Objective To explore dispersion properties of nickalloy/iron package mica powder composite absorbing coatings at different mass fraction ratio.Methods A scanning electron microscope (SEM) was used to observe micro-structures of nickalloy and iron package mica powder. An energy dispersive spectrometer attached to the instrument was used to measure contents of elements in the area selected in samples. Spectra properties of permittivity and permeability of the nickalloy/paraffin and iron package mica powder/paraffin composite materials were studied by vector network an-alyzer. The reflection loss of single layer absorbing coating of different thickness prepared by adding nickalloy and iron package mica powder of different mass ratio in the epoxy resin-polyamide system at frequency band of 2-18 GHz during NRL-arc test.Results Nickalloy in low frequency range had good frequency dispersion properties, which had great effects on the electromagnetic wave magnetic loss. If it was used as a filler of absorbing coatings, it could reduce the quantity of absorbent and the thickness of the coating at the same time. The real part of dielectric constant of iron package mica powder was low. It had good impedance matching with free space and broadened the absorbing bandwidth. When epoxy-polyamide system was used as the matrix resin, a single-layer coating with a 30%/30% quality concentration of both nickalloy/iron package mica powder was prepared, which had a thickness of 1.2 mm. The reflection loss was tested in the frequency range of 2-18 GHz, which showed a minimum reflection of-21.8 dB with a-10 dB bandwidth of nearly 10.5 GHz.Conclusion An absorbing coating with appropriate concentration of both nickalloy and iron package mica powder has good absorbing ability, thin thickness and wide absorbing bandwidth.