【作者】 程斌；

【导师】 徐文骥；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 吸波材料的作用原理是把外来的电磁波能量转换为热能,降低反射波的强度,使雷达无法接收,达到隐身或抗干扰的效果。吸波材料对航空领域、雷达、军用设施等有着重要的意义,已逐渐成为研究热点。目前常用的吸波材料存在着吸波能力有限、或密度大、或频带范围小等缺点,要同时克服以上缺点,对现有吸波材料进行复合,研究制备新型复合吸波材料,将有可能是一条有效的解决途径。六角晶磁铅石型铁氧体,其优点是高的电阻率,较高的饱和磁化强度,吸波能力强,频带应用范围大,但同时也存在密度大、高温特性差等缺点。而金属粉末吸收剂具有良好的温度稳定性,较高的饱和磁化强度,但频带应用范围小。由此可见,铁氧体吸波材料和金属粉末吸波材料的电磁特性具有很强的互补性,若能兼顾二者的优点,有望设计出性能优良的复合吸波材料。但是铁氧体和金属粉末密度都较大,不利于制备出质量轻的吸波材料。为解决这一问题,用质量轻、力学性能好的玻璃微珠为基核,用化学镀和溶胶凝胶法包裹玻璃微珠,有可能得到质量较轻、吸波性能较好的复合复合吸波材料。为此,本文对以下几个方面进行了研究：(1)对玻璃微珠化学镀的前处理工艺进行了研究,探讨了玻璃微珠的清洗工艺及对化学镀的影响；通过选用两种不同的活化剂PdCl2和AgNO3进行活化-化学镀的实验,对比分析了不同的化学镀效果及活化机理。(2)研究了镀液成分、温度、pH值、装载量等因素对玻璃微珠化学镀层性能的影响规律,确定了较好的工艺条件,获得的Ni-P合金镀层饱和磁化强度为2.18emu/g、矫顽力为29.93KA/m。(3)用溶胶凝胶法在玻璃微珠Ni-P镀层表面包裹一层均匀钡铁氧体,涂层厚度较薄。玻璃微珠复合涂层的饱和磁化强度和矫顽力分别为6.59 emu/g,315.6KA/m,电磁性能有所提高。上述工作对丰富复合吸波材料的制备方法具有积极意义。更多还原

【Abstract】 Microwave absorbing materials, converting electro-magnetic energy into heat, reducing the intensity of the reflected wave, to obtain electro-magnetic compatibility, have been widely used in aerospace filed, radar technology and military facilities, and they are researching hotspot in these technology field. The shortcomings of electromagnetic wave absorbent are weak absorption, heavy density, and narrow-bandwidth. To overcome these shortcomings, composite of different absorbents is may be a good solution.The M-type ferrite is thought to be a very important magnetic absorbent for its special properties, such as high resistivity, strong absorption and wide-bandwidth. But the microwave absorption properties of the ferrite are high density. It is hard to use widely because of its density. The microwave absorption properties of ferrite are not as good as metal powder at high frequency. The metal powder is widely used as microwave absorbent for its high specific saturation magnetization, high magnetic susceptibility. But the microwave absorption properties of the metal powder are narrow-bandwidth. The electromagnetic properties of the ferrite and metal powder are complementary. The combination of them is expected to create good electromagnetic wave absorption composite. But the defect of high density is not benefit for the preparation of light absorber. In response to the need for high performance absorber, in this paper, the composite-coating absorbers with hollow cenosphere as nuclear are prepared by sol-gel and electroless plating technology. The main work and achievements of this paper are listed as follow:(1) Fore treatment of electroless Ni-P is studyed:PdCl2 activator and AgNO3 are used as activator in the chemical plating, to compare results and analysis the reason.(2) Study the effect of the solution composition, temperature, PH, loading capacity on the performance of Ni-P coating layer. The best electroless processing is obtained. The magnetic properties of Ni-P coated cenospheres are 8s (2.18emu/g) and He (29.93KA/m).(3) Thin films of Barium hexaferrite are prepared on fly ash cenpsphere particles by sol-gel. The magnetic properties of Ni-P coated cenospheres are 8s (6.59emu/g) and He (315.6KA/m).更多还原