Investigating the electromagnetic wave-absorbing capacity and mechanical properties of flexible radar-absorbing knitted compound materials

2019 ◽  
pp. 152808371987700
Author(s):  
Niuniu Chen ◽  
Sainan Wei ◽  
Bao Shi ◽  
Ruosi Yan ◽  
Xianghong Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Wave ◽  
Convex Surface ◽  
Military Technology ◽  
Radar Absorbing Material ◽  
Compound Material ◽  
Textile Technology ◽  
Aerospace Technology ◽  
Absorbing Material ◽  
Compound Materials

This study fabricated flexible radar-absorbing knitted compound materials by weft knitting and blending ferromagnetic nickel micron-fibers and cotton fiber into structures with a concave–convex surface, including rhombic, mat, wavy, and leno stitches. The electromagnetic wave-absorbing capability and mechanical properties of the flexible radar-absorbing knitted compound materials were evaluated. The results showed that the rhombic, mat, and wavy stitches displayed high mechanical properties with high bursting strength and there were no significant differences among them. The rhombic stitch flexible radar-absorbing knitted compound material with a ferromagnetic nickel micron-fiber content of 14% had a maximum bandwidth of 13 GHz and achieved a minimum reflectance of −20 dB at 7 GHz, which was 150% that of mat fabric, and 200% that of wavy fabric and leno fabric. This was ascribed to the fact that the concave–convex surface with regular diamond-shaped block improved the dispersion of the electromagnetic wave, weakened the wave strength, and increased the interference. Therefore, the rhombic stitch flexible radar-absorbing knitted compound material was the most suitable for flexible radar-absorbing material in this study. The development of flexible radar-absorbing materials, by combining aerospace technology, military technology and textile technology, is important for the application in stealth of aircraft and weapons.

Electron Micro Technology Study on BN Fiber’s Microcosmic Structure and Mechanics Properties

2012 ◽  
Vol 588-589 ◽  
pp. 104-107
Author(s):  
Qing Tian Li
Keyword(s):  
Mechanical Properties ◽  
Scientific Basis ◽  
Manufacturing Technology ◽  
Technology Study ◽  
Compound Material ◽  
Transmission Electron ◽  
Anti Oxidant ◽  
Micro Technology ◽  
Compound Materials ◽  
Analytical Technology

This paper uses transmission electron microscope technology, studies microcosmic structure’ s feature of BN fiber, clarifies existing crystal structure’s state of BN fiber during its producing and transform course. It is studied that BN fiber has a sound mechanical properties, which most of crystalline phase is turbine layer phase and whose nitrogen is high and size is small .During the course of BN fiber’s producing, adding suitable tension from axial can promote directional arrange of BN fiber’s surface crystalline grain and put forward the improving direction of manufacturing technology in order to improve materials’ mechanical properties. BN fiber(indicated by BNf) is a kind of new inorganic material. Because of its fine stable, corrosion-resisting, anti-oxidant properties and high ability of absorbing neutron and so on, it is attached more and more importance and it get constant development and usefulness. BNf and ceramics, metal, various compound materials made of resin material can be used in metallurgy, electron, aviation etc science and technology fields. But the intensity of BNf and its elasticity modulus are lower than basic fundamental material. When BNf’s compound material get fine properties above mentioned, the mechanics properties of the material will drop. So its application degree will be limited to a certain extent. In order to improve and raise BNf’s mechanics properties, this essay makes use of electron micro analytical technology to study its microcosmic structure and mechanics properties, providing scientific basis for designing reasonable manufacturing technology.

Radar Absorbing Materials Based on Metamaterials

2010 ◽  
Vol 75 ◽  
pp. 215-223
Author(s):  
Andrey Nikolayevich Lagarkov ◽  
Vladimir Nikolayevich Kisel ◽  
Vladimir Nikolayevich Semenenko
Keyword(s):  
Electromagnetic Wave ◽  
Reflection Coefficient ◽  
Frequency Band ◽  
Radar Absorbing Material ◽  
Wide Range ◽  
Absorbing Materials ◽  
Different Types ◽  
Absorbing Material ◽  
Wave Incidence

The use of metamaterial for design of radar absorbing material (RAM) is discussed. The typical features of the frequency dependencies of , , ,  of composites manufactured of different types of resonant inclusions are given as an example. The RAM characteristics obtained by the use of the composites are given. It is shown that it is possible to use for RAM design the metamaterials with both the positive values of ,  and negative ones. Making use of the frequency band with negative  and  it is possible to create a RAM with low reflection coefficient in a wide range of the angles of electromagnetic wave incidence.

Properties of Propagation of Electromagnetic Wave in a Multilayer Radar-Absorbing Structure With Plasma- and Radar-Absorbing Material

2011 ◽  
Vol 39 (9) ◽  
pp. 1768-1775 ◽  
Author(s):  
Cheng-Xun Yuan ◽  
Zhong-Xiang Zhou ◽  
Jingwen W. Zhang ◽  
Xiao-Li Xiang ◽  
Yue Feng ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Radar Absorbing Material ◽  
Absorbing Material ◽  
Radar Absorbing Structure

Development of Electroless Ni-P/NRAM Nanocomposite Powder with Enhanced Microwave Absorption Properties

2009 ◽  
Vol 67 ◽  
pp. 59-64 ◽  
Author(s):  
Rahul Sharma ◽  
Ramesh Chandra Agarwala ◽  
Vijaya Agarwala
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
Radiation Power ◽  
Nanocomposite Powder ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Radar Absorbing Material ◽  
Transmission Electron ◽  
Absorbing Material ◽  
Nanocomposite Powders

Nano radar absorbing material (NRAM) i.e. BaMe2Fe16O27 (Me2+=Fe2+) powder (10 nm) is coated with amorphous Ni-P nano layer (5-10 nm) by using electroless (EL) technology to develop EL Ni-P/NRAM nanocomposite powder. The experimental processes parameters and EL Ni-P bath composition were optimized to obtain the deposition. As-deposited nanocomposite powder was microwave annealed (MWA) with increasing radiation power from 160 to 760 watts for 5 minutes. The surface morphology, elemental contents, phase transformation and magnetic properties of NRAM powders were examined under field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) respectively. Maximum reflection loss (RL) 33.75 dB at 15.80 GHz for nanocomposite powder MWA at 760 watt was obtained the absorption range under −15 dB is from 13.76 to 16.77 GHz with 2 mm thickness layer in Ku Band. Excellent microwave absorption properties due to accurate electromagnetic (EM) match in the nanocomposite microstructure, a strong natural resonance and multipolarization. Such (Ni+ Ni3P)/NRAM nanocomposite powders may be attractive candidates for EM absorption.

Sign in / Sign up

Export Citation Format

Share Document