铁氧体/芦苇秆炭复合材料的制备与吸波性能
Preparation and microwave absorption properties of ferrite/reed charcoal composites
简煜 1范勋娥 1邱柏杨 1田迅东 1杨喜1
作者信息
- 1. 中南林业科技大学 材料科学与工程学院,长沙 410004
- 折叠
摘要
为了解决铁氧体吸波材料密度大、吸收带宽窄等问题,以芦苇茎秆为原料,采用常温浸渍及高温原位生长法制备了铁氧体/芦苇秆炭(Ferrite/RC,FRC)复合材料,通过调节碳化温度调控复合材料的电磁特性和电磁波吸收性能.SEM、TEM、XRD、VSM及VNA等结果表明:Ferrite/RC复合材料保留了芦苇秆天然的三维蜂窝状网络结构,Fe3O4及铁纳米颗粒均匀分布在芦苇秆碳壁与孔道中;提升碳化温度(650～690℃)可增大复合材料的电导率与介电损耗能力,但温度过高会导致材料阻抗失配从而降低电磁衰减能力.碳化温度为670℃时制备的复合材料(FRC-670)吸波性能最佳,它在匹配厚度仅为1.7 mm时反射损耗达到-45.7 dB,对应有效吸收带宽为3.4 GHz;在厚度为2 mm时有效吸收带宽为5.7 GHz(12.1～17.8 GHz).其主要的电磁波衰减机制源于复合材料良好的电导损耗、极化弛豫损耗以及电损耗与磁损耗的协同作用.铁氧体/芦苇秆炭复合材料优异的吸波性能在电磁波吸收领域具有良好前景,可促进芦苇资源的高值化与功能化应用.
Abstract
In order to solve the problems of high density and narrow absorption bandwidth of ferrite absorbing materials,the ferrite/reed charcoal(Ferrite/RC,FRC)composites were prepared from reed stalks by impregnation and high temperature in-situ growth methods.The electromagnetic characteristics and electromagnetic wave ab-sorption properties of the composites were controlled by tailoring the carbonization temperature.The results of SEM,TEM,XRD,VSM and VNA show that the Ferrite/RC composites retain the natural three-dimensional honeycomb network structures of the reed stalks,and Fe3O4 and iron nanoparticles are uniformly distributed in the charcoal wall and pores of the reed stem;Raising the carbonization temperature(650-690℃)can increase the conductivity and dielectric loss ability of composites,but excessive temperature can lead to impedance mismatch of the material and reduce its electromagnetic attenuation ability.The composites prepared at a carbonization tem-perature of 670℃ exhibit the best absorption performance,with a reflection loss of-45.7 dB at a thickness of only 1.7 mm and an effective absorption bandwidth of 5.7 GHz(12.1-17.8 GHz)at a thickness of 2 mm,which is attri-buted to the good conductivity loss,polarization relaxation,and the synergistic effect of electrical and magnetic losses of composite materials.The excellent absorption performance of Ferrite/RC composites has good prospects in the field of electromagnetic wave absorption,which can promote the high-value and functional application of reed resources.
关键词
芦苇/Fe3O4/碳化/吸波性能/磁损耗/电磁性能Key words
reed/Fe3O4/carbonization/absorbing performance/magnetic loss/electromagnetic characteristics引用本文复制引用
基金项目
湖南省自然科学基金(S2022JJQNJJ0900)
国家自然科学基金(31901375)
中南林业科技大学人才启动基金(2018YJ033)
出版年
2024
NETL
NSTL
万方数据