Study On Flexible Absorbing Woven Of Ni-Fe Fiber

At present, the absorbing material is mainly focused on the coating of aircraft and weapon, and applied to the rigid structural materials. The space technology, military technology and textile technology are combined, so that the radar canopy cover fabric and base housetent. etc. are developed. And the research significance of flexible stealth materials is important.The topic introduces the sources of Ni-Fe fibers. The microstructure of Longitudinal and cross section were observed with SEM. Then found that the cross section is deformed and irregular, and the surface of longitudinal has a lot of grooves. This is able to increase the holding force between the fibers. The mechanical properties and friction properties of the Ni-Fe fibers were tested and were compared with the stainless steel fibers’. From it, the feasibility of spinning smoothly was confirmed. The reflectance of Ni-Fe fibers was tested and calculated. Compared with silver, copper, aluminum, iron, the reflectance of Ni-Fe fibers is larger. And the magnetic conductivity is high. So it is in favor of the absorption of electromagnetic wave. Permittivity and permeability of Ni-Fe fiber were tested. And the effects of length and content to electromagnetic properties were analyzed with dissipation. It turned out that the electromagnetic loss of Ni-Fe fiber increase with the increases of the fiber length, but first increase and then decrease with the fiber content, because the additional electric field in the conductive grids of fibers is offset with external electromagnetic fields to result in lower absorbing effect of material within2-18GHZ frequencies.Based on the physical properties of Ni-Fe fiber, the orthogonal design was adopted to determine the parameters including roving twist, multiple spinning back drafts and yarn twist, the strength and wear resistance of5yarns produced were tested and analyzed. The result shows that the suitable drawing numbers are adopted to solve the problem of mixing uniformity of Ni-Fe Fibers. And the appropriate roving twist, multiple spinning back drafts and yarn twist are key factor of resultant yarn.Ni-Fe woven, stainless steel woven and multilayer fabric were process designed and weaved. And the mechanical properties of Ni-Fe woven were tested to ensure the basic performance requirements of the application. The reflectance of fabrics was tested within2-18GHZ frequencies by VNA. And the measured data was processed by Origin to analyze the absorbing properties of different absorbing materials in different frequencies. The results indicate that in2-18GHZ frequencies, the absorbing effect of3/1twill is better than the plain weave and8/5diagonal in Ni-Fe woven, absorbing property first increase and then decrease with the increase of stainless steel content at low levels in double cloth, the Ni-Fe layers are more, the fabric absorbing effect is better in Three layer overlay fabrics, and the absorbing properties of four levels orthogonal woven fabrics are better than three levels orthogonal woven fabrics.