【作者】 高正娟；

【导师】 曹茂盛；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2003， 硕士

【摘要】 目前，一类非常重要且在国内已得到实用的微波吸收材料是在高分子粘结剂基体中加入超细颗粒制成的混合物，这种材料既可以用于涂覆型吸波材料又可用于结构型吸波材料中的某一层。本文将此混合物称之为颗粒分散体系。单层吸波材料的吸波性能主要取决于材料的复介电常数、复磁导率、材料厚度及使用频率等因素，而该层的宏观电磁参数又取决于各组分的电磁参数及其含量。从电磁参数ε和μ出发研究吸波材料的电磁性能对准确预测材料的吸波性能、缩短设计周期具有极其重要的意义。 本文对羰基铁粉／环氧颗粒分散体系的电磁性能进行研究，包括体系的等效电磁参数的测量和计算，体系基体、颗粒含量、厚度等对吸波性能的影响等。体系的宏观电磁参数可通过HP8722ES矢量网络分析仪测得。对难以获得准确电磁参数的颗粒吸收剂，提出了根据不同含量分散体系的电磁参数利用曲线拟合和样条插值求解的方法。Maxwell-Garnett公式和Bruggeman公式是适用球形颗粒复合体系的经典计算公式，本文将两组公式及Maxwell-Garnett扩展公式运用于羰基铁粉分散体系。f＜15％时，Maxwell-Garnett公式和Bruggeman公式均可准确地预测该体系的等效电磁参数；扩展Maxwell-Garnett公式比经典公式更准确地描述了体系等效电磁参数。此外，根据电磁波在介质中传输的阻抗理论计算了单层羰基铁粉分散体系的反射率，并考虑了不同基体、羰基铁粉含量及体系厚度对反射率的影响。论文主要以DT-50／环氧分散体系为例来说明计算情况。更多还原

【Abstract】 At present, a composite medium in which ultrafine particles are dispersed in another originally homogeneous polymer (matrix) is an important absorbing material and has been used widely. This kind of material can be used both in coatings and in structure materials. This paper calls it particles disperse system(DS). Absorbing properties of single layer absorbing materials are determined by complex permittivity, complex permeability, thickness, frequency and so on. The external electromagnetic (EM) parameters of materials lie on ingredients’ content and EM parameters. The effective EM parameters of composite medium can be calculated, so we can optimize absorbing materials by predicting reflection and cut design outlay and periods.This paper investigates the EM properties of carbonyl-iron/epoxy DS, including measuring and calculating the EM parameters of the DS, the influence of matrix, particles content and thickness on absorbing properties. A HP8722ES network analyzer can measure the external EM parameters. We can infer the EM parameters of pure carbonyl-iron from the EM parameters of DS of various content by curve-fit simulating and interpolation. Maxwell-Garnett(MG) formula and Bruggeman formula is applicable for spherical particles DS. This paper evaluates the application of these two formula and their extend formula to carbonyl-iron/epoxy disperse system. MG and Bruggeman formula can predict EM parameters of carbonyl-iron/epoxy DS when f<15%, and Extended MG formula is more accurate than MG. Based on impedance theory of EM wave transmitting in medium, we calculate the reflection of single-layer carbonyl-iron/epoxy DSand discuss the influence of matrix type, carbonyl-iron content and thickness on absorbing properties.更多还原