【作者】 郑夏莲；

【导师】 朱正吼；

【作者基本信息】 南昌大学 ， 材料学， 2014， 博士

【摘要】 结构型吸波复合材料是兼顾吸波性能和力学性能的雷达波隐身材料，具有可设计性强、吸波频带宽、承载与吸波有机结合、增重小、可避免表面涂层脱落等优点，是当前最受瞩目的研究领域之一。本文较系统地研究了结构型吸波复合材料层合板的设计、层合板制备技术、吸波剂制备技术与表征、玻璃纤维表面磁改性、环氧树脂磁改性、吸波剂/环氧树脂复合树脂电磁特性、S玻璃纤维/环氧树脂复合材料吸波性能和力学性能、复合材料吸波性能优化技术等内容，取得了很多有应用价值的研究成果。（1）在复合材料吸波性能设计方面，针对两种典型类型的结构型吸波复合材料的吸波性能和力学性能进行了设计。针对单层铺层的吸波性能设计难题，提出了等效网格法设计思想，将整体铺层抽象成一个由片状“环氧树脂粉体”均匀分布的复合材料，计算出铺层的等效电磁参数。（2）在吸波剂研制方面，采用“退火脆化+高能球磨”工艺制备了400目FeCuNbSiB非晶粉体，在非晶粉体基础上，通过晶化退火处理，得到软磁性能优异的FeCuNbSiB纳米晶粉体，粉体晶粒尺寸15nm左右，粉体呈现片状，粉体采用SiO2包覆；采用液相还原法制备了球形超细Ni粉体，单个粉体粒径60¹00nm，团聚体粒径约250³00nm；采用碳还原法制备了氧化锌晶须；采用“化学共沉+高温助熔”工艺分别制备出六角晶系Ba（Zn0.75Co0.25）2Fe16O27铁氧体粉体和Ba（Zn0.25Co0.75）2Fe16O27铁氧体粉体，粉体经过400目筛分后得到粒径小于38μm的铁氧体粉体。比较分析了FeCuNbSiB纳米晶粉体、超细Ni粉体、FeSiAl粉体、六角晶系Ba（Zn0.75Co0.25）2Fe16O27铁氧体粉体和Ba（Zn0.25Co0.75）2Fe16O27铁氧体粉体吸波剂的电磁参数，每种吸波剂均具有特点。具有良好吸波性能的吸波剂是FeCuNbSiB纳米晶粉体、FeSiAl粉体、超细Ni粉体。（3）针对玻璃纤维表面磁改性，研究了一种具有良好电磁波吸收特性的玻璃纤维布的制备方法。采用液相还原法制备了纳米铁镍合金粉体，利用纳米粉体的物理吸附特性使粉体在玻璃纤维布中得到很好地分散，该粉体填充在玻璃纤维布表面和缝隙里，最终得到具有优良的电磁性能的玻璃纤维布。制备出的吸波玻璃纤维呈现出金属色泽，粉体与布结合力好，有一定的磁性。（4）开发了吸波剂梯度分布的结构型复合材料RTM成型技术。开发了应用于SMC成型方法的预浸料工艺，找到了环氧树脂触变剂和环氧树脂预浸料专用固化剂。制备的复合材料层合板，树脂基体与纤维界面结合牢固，尺寸稳定、表面光洁、阻燃。S玻璃纤维/环氧树脂复合材料层合板具有优良的力学性能：拉伸强度大于500MPa，弯曲强度大于400MPa。（5）研究了FeCuNbSiB纳米晶粉体、超细Ni粉体、铁氧体（0.25）、铁氧体（0.75）四种吸波剂在橡胶基体中的吸波性能。研究表明，FeCuNbSiB纳米晶粉体和超细Ni粉体具有良好的吸波性能，尤其是400目的FeCuNbSiB纳米晶粉体吸波性能最佳。吸波性能最佳和最具有实用价值的材料是“80wt%FeCuNbSiB纳米晶粉体（400目）/橡胶材料”，其tan e+tan m的值在2¹2GHz频率范围内0.6¹.4，值0.23，材料与玻璃纤维/环氧树脂材料阻抗匹配。该材料可以作为玻璃纤维/环氧树脂复合材料层合板中的夹层，承担吸波功能。（6）研究了FeCuNbSiB纳米晶粉体、超细Ni粉体、铁氧体（0.25）、铁氧体（0.75）四种吸波剂在环氧树脂基体中的吸波性能。研究表明，FeCuNbSiB纳米晶粉体和超细Ni粉体具有良好的吸波性能，尤其是400目的FeCuNbSiB纳米晶粉体吸波性能最佳。FeCuNbSiB纳米晶粉体/环氧树脂材料的整体吸波特征为：在2².5GHz频率范围内随频率f增加而显著降低，值在2GHz时为4⁶，在2.5GHz时大幅度降低到1.5，在大于4GHz时值约为1；吸波剂含量越高，值越大。值随频率的变化规律与值相同；材料在频率大于2.5GHz时与玻璃纤维/环氧树脂铺层的阻抗匹配，而在频率2².5GHz时与空气阻抗匹配；吸波剂含量越高，其磁损耗角正切值tan m值越大，而且在2.5¹2GHz频带内一直非常稳定，显示了良好的宽频特性。FeCuNbSiB粉体/环氧树脂体系是最好的吸波基体材料。对于RTM成型、模压成型方法，选取50wt%FeCuNbSiB粉体/环氧树脂体系能够兼顾材料的成型性能和吸波性能；对于夹层层合板、SMC成型来说，可以选取80wt%FeCuNbSiB粉体/环氧树脂体系。50wt%FeCuNbSiB粉体/环氧树脂体系中粉体积含量很低（11%），整个体系具有良好的流动性；50wt%FeCuNbSiB粉体/环氧树脂体系的磁损耗角正切值tan m值在2¹2GHz频带内一直波动在0.3左右，具有良好的宽频吸波性能。在阻抗匹配方面，在频率大于2.5GHz时与玻璃纤维/环氧树脂铺层的阻抗匹配（≈0.25），而在频率2².5GHz时与空气阻抗匹配（≈1）。较50wt%FeCuNbSiB粉体/环氧树脂体系，80wt%FeCuNbSiB粉体/环氧树脂体系的吸波性能更优，但树脂流动性较差，因此适合于夹层层合板、SMC成型。（7）以80wt%FeCuNbSiB粉体/环氧树脂为基体树脂，以S玻璃纤维为增强材料制备的复合材料层合板具有良好的综合吸波性能。板的表面反射系数衰减约为（-4）^-5dB，tan m值约为0.4⁰.5，tan e+tan m值约为0.5⁰.6，与空气的匹配厚度约为1.2²mm。在层合板前方增加S玻璃纤维/环氧树脂铺层（即透波层）作为阻抗匹配层后，层合板的吸波性能显著增加。由透波层（1.62mm吸波玻璃纤维/环氧树脂）和吸波层（1.73mmFeCuNbSiB粉体/环氧树脂）组成的双层复合材料板具有优异的吸波特性：R≤-4dB的合格带宽达到了14.24GHz（3.76-18GHz），R≤-6dB的合格带宽达到了11.92GH（z4.4-8.8GHz，9.68-10.4GHz，11.2-18GHz）。（8）通过梯度铺层设计成功地进一步提高了复合材料层合板的吸波性能。当采用FeCuNbSiB纳米晶粉体为吸波剂，复合材料层合板的厚度为4mm时，在2⁸GHz时R＜-4dB、在8¹8GHz时R＜-8.5dB，具有良好的宽频吸波性能。当采用FeSiAl粉体为吸波剂，层合板由2.12mm的玻璃纤维/环氧树脂透波层和2mm的FeSiAl粉体/环氧树脂吸波层（0.5mmFeSiAl粉体/环氧树脂+0.5mm玻璃纤维/环氧树脂+1mmFeSiAl粉体/环氧树脂）组成，层合板厚度为4.1mm时，层合板吸波性能为：频率4.08-4.56GHz和15.6-16.48GHz范围内，R＜-4dB；当频率在4.56-15.6GHz范围内，R＜-6dB。（9）利用碳纤维和S型玻璃纤维按照1:1比例混编在一起的混杂纤维铺层技术可以有效调整层合板的吸波频带位置，起到定频段设计吸波性能的效果。（10）利用模块化设计可以有效拓宽层合板的吸波频带。模块化设计了厚度为4mm的FeSiAl粉体/环氧树脂复合材料层合板，层合板由（2.7mm玻璃纤维/环氧树脂+1.3mmFeSiAl/环氧树脂）和（2mm玻璃纤维/环氧树脂+2mmFeSiAl/环氧树脂）两部分组成。层合板具有优异的电磁吸收特性：当频率在2.24-3.76GHz，8.56-11.76GHz，和16.24-17.2GHz范围内，-6dB＜R＜-4dB；当频率3.76-8.56GHz和11.76-16.24GHz范围内，R＜-6dB。模块化设计了厚度为4mm的FeSiAl粉体/环氧树脂复合材料层合板，层合板由（2.46mm透波层+1.56mmFeSiAl吸波层）和（2.11mmFeSiAl吸波层+1.5mmFeCuNbSiB吸波层+0.4mm透波层）两部分组成。层合板具有优异的电磁吸收特性：在2-18GHz范围内，R值均小于-4dB；R值小于-6dB的合格带宽达到了12.96GHz（2-6.48GHz，9.52-18GHz），在6.48-9.52GHz频率范围内，R值均接近-6dB。（11）本文设计和制备的结构型吸波复合材料层合板吸波性能和力学性能优异：在厚度不大于4mm时，吸波性能2-18GHz，R≤×××。层合板力学性能：拉伸强度≥500MPa、抗弯强度≥400MPa；复合材料密度≤2.5g/cm3；复合材料具有良好的成型性能。更多还原

【Abstract】 Structural absorbing material is radar stealthy material which has waveabsorbing properties and mechanical properties. It has strong design, absorbing bandwidth, bearing and absorbing organic combination, small weight, avoiding surfacepeeling coating, etc, which is one of the most notable material.This paper systematically studies design of the structural absorbing compositelaminated plate, preparation technology of laminated plates, preparation technologyand characterization of absorbents, surface modification of glass fiber, magneticmodified of epoxy resin, electromagnetic characteristics of absorbing agent/epoxyresin composite resin, absorbing performance and mechanical properties of S glassfiber/epoxy resin composites, optimization techniques of absorbing performance, etc,which has made a lot of research achievements of application value.（1） In the aspect of wave absorption performance design of the composite: waveabsorption performance and mechanical performance of the two typical types ofstructural absorbing wave composite materials have been designed. For the designproblem of single layer absorbing performance, the method of equivalent grid designidea was put forward, overall layer was abstractively thought as composite material ofa flake “epoxy resin powder” uniform distribution, equivalent electromagneticparameters of the layer were calculated.（2） In terms of development of absorbing agent:400meshes FeCuNbSiBamorphous powders were prepared adopting "annealing embrittlement andhigh-energy ball mill" process. Based on the amorphous powder, FeCuNbSiBnanocrystalline powders of excellent soft magnetic performance were gotton bymeans of crystallization annealing treatment which are around15nm, flake, SiO2coated. The spherical ultrafine Ni powders were prepared by liquid phase reductionmethod, which particle size of a single powder is60¹00nm, particle size ofaggregate is about250³00nm. Zinc oxide whisker was prepared by carbonreduction method. The hexagonal system Ba（Zn0.75Co0.25）2Fe16O27ferrite powdersand Ba（Zn0.25Co0.75）2Fe16O27ferrite powders were prepared by “chemical coprecipitation and high temperature to melt” process, particle size of the ferritepowder is less than38μm after400meshes selected. Electromagnetic parameters ofFeCuNbSiB nanocrystalline powder, ultrafine Ni powder, FeSiAl powder, hexagonalsystem Ba（Zn0.75Co0.25）2Fe16O27ferrite powder and Ba（Zn0.25Co0.75）2Fe16O27ferritepowder were analyzed. Every absorbing agent has characteristics. Good absorbingproperties of the absorbing agents are FeCuNbSiB nanocrystalline powders, FeSiAlpowder, ultrafine Ni powder.（3） In terms of surface modification of magnetic glass fibers, a preparationmethod of glass fiber cloth of good electromagnetic wave absorption properties hasbeen studied. Nanometer iron nickel alloy powders were prepared by liquid phasereduction process. Nano powders are well dispersed in glass fiber cloth using thephysical adsorption properties. Powders are filled in the cracks and the surface of theglass fiber cloth. Finally glass fiber cloths of good electromagnetic performance weregotton. Absorbing glass fiber is metal color, excellent adhesion, of a certainmagnetism.（4） The RTM molding technology of structural composites of the gradientdistribution of absorbent have been developed. The prepreg process was applied tothe SMC forming method, and the thixotropic agent of epoxy resin and the specialcuring agent of epoxy resin presoak were found. The interface combination of resinmatrix and fiber is strong in the composite material laminated plates, which are madein this study, with dimensional stability and smooth and clean surface and inflamingretarding. S glass fiber/epoxy composite laminates have excellent mechanicalproperties which tensile strength is greater than500MPa and bending strength isgreater than400MPa.（5） Absorbing performance of rubber matrix with four kind of absorbing agent,named FeCuNbSiB nanocrystalline powders, ultrafine Ni powders, ferrite（0.25） andferrite（0.75）, have been studied. Researches show that FeCuNbSiB nanocrystallinepowders and ultrafine Ni powders have good absorbing performance, especiallyabsorbing performance of FeCuNbSiB nanocrystalline powders with400meshes isbest.The material with the best absorbing performance and the most practical value is 80wt%FeCuNbSiB nanocrystalline powders （400meshes）/rubber compositematerial, which value of tan eand tan mis between0.6and1.4in2¹2GHzand which μ/ε is0.23. And the impedance of material and glass fiber/epoxy resinmaterial is matching. And this material can be used as interlining of glass fiber/epoxyresin composite material laminated plates, with its good absorbing function.（6） The Absorbing properties of four kinds of absorbing agents in epoxy resinmatrix have been studied in this paper. The absorbing agents are FeCuNbSiBnanocrystalline powder, ultrafine Ni powder, ferrite（0.25） and ferrite（0.75）. Studiesshow that FeCuNbSiB nanocrystalline powder and ultrafine Ni powder have goodabsorbing properties, especially the performance of400meshes FeCuNbSiBnanocrystalline powder is best.The integral absorbing characteristics of FeCuNbSiB nanocrystallinepowder/epoxy materials: when frequency is in the range of2².5GHz, it decreasessignificantly with increase of frequency. The value is4⁶when the frequency is2GHz, and it reduces to1.5when the frequency is2.5GHz. And the value isabout1when the frequency is higher than4GHz. The value is greater when theabsorbing agent content is higher. The material matches with impedance of fiberglass/epoxy plies when the frequency is higher than2.5GHz. It matches with theimpedance of the air in2².5GHz frequency range. The tan mvalue becomeslager with increasing levels of absorbing agent, which has been very stable within2.5¹2GHz band, shows excellent broadband characteristics.FeCuNbSiB nanocrystalline powder/epoxy material is the best absorbingmaterial. Formability and absorbing properties of50wt%FeCuNbSiB powder/epoxysystem can be very good by RTM molding or compression molding method. Forplywood sandwiched layers by SMC molding method, we can select80wt%FeCuNbSiB powder/epoxy system.Powder volume content of50wt%FeCuNbSiB powder/epoxy system is verylow （11%）. The whole system has good mobility, the tan mof50wt%FeCuNbSiBpowder/epoxy system has been fluctuating around0.3within2¹2GHz band, whichshows a good broadband absorbing properties. In the aspect of impedance matching:when the frequency is above2.5GHz, it matchs with the impedance of glass/epoxy laminate （≈0.25）. When frequency is2².5GHz, it matches with impedance ofair （≈1）.Compared50wt%FeCuNbSiB powder/epoxy resin system, absorbingperformance of80wt%FeCuNbSiB powder/epoxy resin system is better, butliquidity of resin is poorer, therefore it is suitable for SMC molding layers ofplywood.（7） The composite laminated plates with80wt%FeCuNbSiB powder/epoxyresin as matrix resin, and S glass fiber as reinforced material have goodcomprehensive absorbing properties.The attenuation of the surface reflectioncoefficient of the panels is about （-4）^-5 dB, the value of the tan mis0.4⁰.5, thevalue of the tan e+tan mis0.5⁰.6, and the matching thickness with the air is1.2²mm. After increasing S glass fiber/epoxy resin layer （that is through wavelayers） in front of the laminated plates as the impedance matching layer, theabsorbing properties of the laminated plates improve significantly. The doublecomposite materials which composed of through wave layer （1.62mm absorbingglass fiber/epoxy resin） and absorbing layer （1.73mm FeCuNbSiB powder/epoxyresin） have excellent electromagnetic absorbing properties: the qualified bandwidth ofR≤-4dB reaches14.24GHz （3.76-18GHz）, the qualified bandwidth of R≤-6dBreaches11.92GHz （4.4-8.8GHz,9.68-10.4GHz,11.2-18GHz）.（8） The absorbing properties of the composite laminated plates were improvedsuccessfully by the gradient layer design. When using the FeCuNbSiBnanocrystalline powders as the absorbing agent, and the thickness of the compositelaminated plates is4mm, R<-4dB within2⁸GHz, R<-8.5dB within8¹8GHz,have a good broadband absorbing properties. When using the FeSiAl powders as theabsorbing agent, laminated platescomposed of2.12mm glass fiber/epoxy resinthrough wave layers and2mm FeSiAl powder/epoxy resin absorbing layer （0.5mmFeSiAl powder/epoxy resin and0.5mm glass fiber/epoxy resin and1mm FeSiAlpowder/epoxy resin）, and the thickness of the laminated plates is4.1mm, theabsorbing properties of the laminated plates is: R<-4dB within the frequency4.08-4.56GHz and15.6-16.48GHz, R<-6dB within the frequency4.56-15.6GHz.（9） The hybrid fiber layer technology using carbon fiber and S type glass fiber according to the proportion of1:1mix together to achieve the effect of designingabsorbing properties at a fixed frequency, can effectively adjust the absorbing bandposition of the laminated plates.（10） Using the modular design can effectively broaden absorbing band of thelaminated plates.The thickness of4mm FeSiAl powder/epoxy resin composite laminated boardwas designed by modular method. Laminated plate is composed by （2.7mm glassfiber/epoxy resin+1.3mm FeSiAl/epoxy resin） and （2mm glass fiber/epoxy resin+2mm FeSiAl/epoxy resin） of two parts. Laminated plates have excellentelectromagnetic absorption properties:6dB<R<-4dB in2.24³.76GHz,8.56¹1.76GHz, and16.24¹7.2GHz ranges, R<-6dB in3.76⁸.56GHz and11.76¹6.24GHzfrequency ranges.Composite material plate formed by one part （2.46mm through wave layer+1.56mm FeSiAl absorbing layer） and the other part （2.11mm FeSiAl absorbing layer+1.5mm FeCuNbSiB absorbing layer absorbing layer+0.4mm through wave layer）shows the excellent electromagnetic absorption characteristics: R values are less than-4dB in2¹8GHz range, qualified bandwidth of R value less than-6dB reachs12.96GHz （2⁶.48GHz and9.52¹8GHz）, R values are close to-6dB within thescope of6.48to9.52GHz.（11） Structural absorbing composite laminated plate is of excellent waveabsorption performance and mechanical performance: no greater than4mm inthickness. The absorbing performances: R≤×××in2¹8GHz range. The mechanicalproperties: tensile strength≥500MPa, flexural strength≥400MPa, density ofcomposite material≤2.5g/cm3. Composite material is of good formability.更多还原