介电型复合吸波涂层结构与特性研究

发布时间：2019-04-27 01:49

【摘要】：伴随着信息化社会飞速发展,各类电子机械产生的电磁辐射越来越严重。电磁辐射防护和环境电磁污染的治理已引起国际社会的高度重视,电磁波吸收材料更成为科技及产业界的研究热点。电磁波吸收涂料以其少占空间、不受表面形状限制、应用灵活等特点,成为电磁辐射防护材料的重要研究方向,特别是军事隐身应用,其研究具有重大现实意义。目前传统的吸波涂料主要采用磁性材料如铁氧体、羰基铁等,存在密度大、吸收频带窄、结合力差等问题,无法满足现实应用需求。制备“宽、轻、薄、强”的吸波涂料刻不容缓。本文探索通过理论设计,采用介电材料进行吸波涂料制备,旨在利用介电材料轻质、易与基材复合、电磁参数可调等特点,克服磁性材料的缺点,制备出高性能的吸波涂层。整个实验以导电炭黑、碳纤维为吸波剂,环氧树脂为基材进行吸波材料制备,通过对单层、多层等的系列研究,创新性实现了吸收特性好、轻质宽频吸收涂层的研制成功。本文首先研究单层涂层结构,通过对纤维长度和含量、炭黑含量对涂层吸波性能的影响研究,发现：纤维长度为2mm、含量为0.3%时吸波效果最好；吸波性能随长度或含量的递增先增大再减小,峰位向低频移动。单层涂层存在吸收频带窄、峰值较小现象。多层复合涂层研究表明：上层为碳纤维,即碳纤维涂层为阻抗匹配层时,吸收频带较窄；采用炭黑涂层为阻抗匹配层时,吸波效果较好；第一层炭黑含量为16%、厚度为1.5mm,第二层碳纤维含量为0.3%、厚度为1.5mm时吸波效果最佳,在8.7-18GHz范围内吸收量低于-lOdB；三层复合涂层研究表明,当第一层炭黑含量为16%、厚度为1.5mm,第二层碳纤维含量为0.3%、厚度为0.5mm,第三层碳纤维含量为0.5%、厚度为lmm时,可实现8-18GHz频带吸收量都在-1OdB以下。进一步深化研究。通过理论设计,采用多层夹膜结构进行高性能吸波涂层制备。采用炭黑为导电填料制备了环氧树脂/电阻膜三层三膜复合吸波体,研究表明,涂层总厚度为4mm、电阻膜分别约为300、500、1000Ω/□,在8-18GHz频段内反射率都在-lOdB以下,其中最大峰值为-18.5dB；采用碳纤维膜代替电阻膜,研究发现：涂层在4.8-18GHz频带吸收量都在-8dB以下,而在5-7.8GHz、13-18GHz频带吸收量都在-10dB以下,最大吸收量为-12.2dB,实现了超宽的吸收效果。
[Abstract]:With the rapid development of information society, electromagnetic radiation produced by all kinds of electronic machinery becomes more and more serious. Electromagnetic radiation protection and the control of environmental electromagnetic pollution have been attached great importance to by the international community, and electromagnetic wave absorbing materials have become the research hotspot of science and technology and industry. Electromagnetic wave absorbing coating has become an important research direction of electromagnetic radiation protection materials, especially for military stealth application, because of its characteristics of less space occupation, no limitation of surface shape, flexible application and so on. The research of electromagnetic wave absorbing coating is of great practical significance. At present, magnetic materials such as ferrite and carbonyl iron are mainly used in traditional microwave absorbing coatings. There are many problems, such as large density, narrow absorption band and poor binding force, which can not meet the needs of practical application. The preparation of "wide, light, thin, strong" absorbing coating is urgent. This paper explores the preparation of microwave absorbing coatings with dielectric materials through theoretical design. The purpose of this paper is to make use of the light weight of dielectric materials, easy to composite with substrate and adjustable electromagnetic parameters, to overcome the shortcomings of magnetic materials, and to prepare high performance absorbing coatings. In the whole experiment, conductive carbon black, carbon fiber as absorbing agent and epoxy resin as base material were used to prepare absorbing material. Through a series of studies on single layer and multi-layer, the excellent absorption property and light broadband absorption coating were successfully developed. In this paper, the structure of monolayer coating was studied firstly. The effects of fiber length and content, carbon black content on the absorbing properties of the coating were studied. It was found that the microwave absorbing effect was the best when the fiber length was 2 mm and the content of carbon black was 0.3%. The absorption performance increases first and then decreases with the increase of length or content, and the peak position moves to low frequency. The absorption band of monolayer coating is narrow and the peak value is small. The study of multi-layer composite coating shows that the upper layer is carbon fiber, that is, when carbon fiber coating is impedance matched layer, the absorption frequency band is narrow, and the absorbing effect is better when carbon black coating is used as impedance matching layer. When the content of carbon black in the first layer is 16%, the thickness is 1.5 mm, and the content of carbon fiber in the second layer is 0.3%, the absorbing effect is the best when the thickness is 1.5mm, and the absorption amount in the range of 8.7-18GHz is lower than-lOdB;. The results show that when the content of carbon black in the first layer is 16%, the thickness is 1.5 mm, the content of carbon fiber in the second layer is 0.3%, the thickness is 0.5 mm, the content of carbon fiber in the third layer is 0.5%, and the thickness is lmm. The absorption of 8-18GHz band is below-1OdB. Further deepen the research. Through the theoretical design, multi-layer coating structure was used to prepare high performance absorbing coating. Epoxy resin / resistance film three-layer three-film composite absorbers were prepared by using carbon black as conductive filler. The results show that the total thickness of the coating is 4mm, the resistive film is about 300,500,1000 惟 / -, and the reflectivity is less than-lOdB in 8-18GHz band. The maximum peak value was-18.5 dB; The carbon fiber film is used to replace the resistive film. It is found that the absorption of the coating in the 4.8-18GHz band is less than-8dB, while in the frequency band of 5 ~ 7. 8GHz, the absorption in the frequency band of 13 ~ 18GHz is below-10dB, and the maximum absorption is-12.2dB, and the maximum absorption of the coating is-12.2dB. The ultra-wide absorption effect is achieved.
【学位授予单位】：海南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB34

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