多层异构复合材料的制备及吸波性能

Preparation and microwave absorption performance of multilayered heterogeneous composite materials

通过模板法与物理混合法相结合,成功制备了三维网络结构的BaTiO_(3)(BTO)+Fe_(3)O_(4)三聚氰胺泡沫异质结构复合材料,采用扫描电镜和X射线衍射对复合材料样品的表面形貌和晶体结构进行了表征,并使用矢量网络分析仪测试了该样品在2~18 GHz频率范围内的复介电常数和复磁导率,并根据测量数据计算了反射损耗值。随后,使用COMSOL多物理场仿真软件进行有限元分析,研究了该复合体系的吸收机制和吸波性能。结果表明:成功引入了BTO和Fe_(3)O_(4)形成的大量异质界面到三维网络结构碳中,构建了异质结构。BTO和Fe_(3)O_(4)优化了三维网络结构的阻抗匹配,从而显著提高了多层异构复合材料的有效吸收带宽。此外,BTO、Fe_(3)O_(4)和三维网络碳结构构筑成了高气孔率的三维网络,导致电磁波在材料内部发生多次反射和散射,增强了电磁波与材料之间的相互作用,实现了对电磁波的吸收,提升了吸波效率。该复合材料展示了出色的吸波性能,当复合材料的厚度为2.9 mm时,最强的反射损耗值达到−54.76 dB,而当复合材料的厚度为2.7 mm时,有效吸收带宽提升至7.92 GHz。

The BaTiO_(3)(BTO)/Fe_(3)O_(4)/melamine foam heterostructure composites with three-dimensional network structure were prepared using a combined template method and physical mechanical mixing method,where the scientific control group was prepared using a component control method.The surface morphology and crystal structure of the samples were characterized by scanning electron microscopy and X-ray diffractometry.To evaluate the complex permittivity and permeability of the samples in the frequency range of 2−18 GHz,a vector network analyzer was used,and the reflection loss value was calculated based on the measured experimental data.The absorption mechanism and performance of the composite system were explored through finite element analysis using COMSOL software.The results show that a large number of heterogeneous interfaces generated are successfully introduced by BTO and Fe_(3)O_(4)into the three-dimensional carbon network structure,resulting in a heterogeneous structure.Moreover,BTO and Fe_(3)O_(4)optimize the impedance matching of the three-dimensional network structure,significantly improve the effective absorption bandwidth of the multilayered heterogeneous composite materials.The high porosity three-dimensional network composed of BTO,Fe_(3)O_(4)and three-dimensional carbon network structure leads to multiple reflections and scattering of electromagnetic waves inside the material,achieving the improved absorption efficiency.When BTO and Fe_(3)O_(4)powder are evenly mixed and added to melamine foam,achieving the mass of loaded particles reaching up 30%(mass fraction)of the total mass of foam,the strongest reflection loss value at the thickness of 2.9 mm reaches up to−54.76 dB.Furthermore,the effective absorption bandwidth is significantly widened to 7.92 GHz at the thickness of 2.7 mm.