| With the development of infrared detection technology, the aircrafts’ now are facing severe challenge. There are several ways to infrared stealth, due to the infrared coating has a simple preparation process and excellent performance, which has been widely used in practice. For practical applications, in the band of 3-5 micrometer and 8-14 micrometer, the emissivity should be as low as possible. Because of the low infrared emissivity of flake aluminum has been widely used in the preparation of the infrared coating. However, since the metallic pigment typically has strong metallic luster and a high visible light reflectance, which is unfavorable for visible light camouflage. Due to the diversification detection of modern military warfare, the material to meet only one aspect of the needs has been increasingly unable to meet the needs of modern warfare. Therefore, to design one kind of material that can be compatible with visible light-infrared-radar absorbing properties have great significance for practical applications.Fe3O4 is a black ferrite material, and its visible brightness value is low, While Fe3O4 is a magnetic material, which has been widely used in radar absorbing coatings. But Fe3O4 is also a highly infrared-absorbing material, which is unfavorable for the infrared camouflage. Powder modification technique is an important method for preparing of composite material. By the method of coating one kind of particles to the surface of another one to form a kind of material which usually have some properties of the two kind of materials.This paper has prepared Fe3O4 powder under the condition of solvothermal environment. The properties of magnetic, the reflectance of visible light and infrared band and the absorption of radar band have been analyzed. Analytical testing have demonstrated that Fe3O4 is a black pigment. Its brightness value is very low,which is 19.18, The real part of the dielectric constant at 0.5-10 GHz is about 13, the initial permeability 2.7 around, and the saturation magnetization is 64.49 emu / g. By the way of coating a layer of Fe3O4, which can be effectively compatible the visible light and the waveband of radar, which provides an experiment basis for the coating.Aluminum powder was coated by a layer of iron oxide to form a golden like powder with the direct precipitation method. Then the dark pigment was prepared under the environment of ethylenediamine solvothermal condition with the powder has been prepared. SEM and XRD were used respectively to analyze the morphology and phase structure of the composite powder. Fourier transform infrared spectroscopy with an integrating sphere attachment was used to te st the infrared reflectance of the composite powder. The UV/VIS/NIR spectrophotometer was used to characterize the properties of reflection in the visible and near-infrared bands. The Saturation magnetization parameters are characterized using PPMS, and using vector network to analysis the dielectric properties and permeability characteristics of the material.The reaction temperature, the amount of coating, concentration and other conditions of the preparation have effects on the final product performance. The Results have shown that sodium dodecyl benzene sulfonate was used as surfactant, the reaction temperature is 40 ℃,the molar ratio of Na2CO3 and Fe Cl2 equal to 1:1, the stirring speed at the rate of 400 r/min to 600 r/min,the coating amount about 0.1:1 to 0.15:1,and the products have a brightness value of the visible light in the range of 62.2 to 53.6, the infrared emission in the range of 0.46 to 0.51. Meanwhile, the saturation magnetization are between 17.3 to 23.07 emu/g. After the coating, the dielectric properties have a significantly decrease, which can be effectively compatible with the visible and radar stealth.Finally, the crystalline and morphology prepared at different calcination temperature, Which has been shown that the material of high crystallinity material there has a significant decrease of the yellow hue. |
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