Metamaterial stealth coating resonant radar absorbing material and non resonant radar absorbing material

This type of material is almost no longer a secret. The first method is to make the coating thickness consistent with the wavelength of the radar wave, which can absorb most specific frequency signals. Once effective, the efficiency is very high. And another type of non resonant magnetismRadar absorbing materialIt is based on magnetic materials and specifically absorbs radar waves of a certain frequency. For example, the F22 fighter jet in the United States is coated with a composite of gallium oxide and silver. Although it has excellent absorption performance, it is very delicate, requires careful maintenance, and is highly toxic.

Metamaterial stealth coating

This is an extremely advanced stealth coating, and electromagnetic metamaterials are currently the latest direction of stealth material development. China's J-20 fighter jet uses metamaterial stealth coating. It is reported that this metamaterial was designed and developed by a research team in a State Key Laboratory in Nanjing.

Metamaterials are a class of equivalent uniform artificial composite materials with extraordinary physical properties. Metamaterials are composed of artificial microstructures, and by designing different microstructures, the relative equivalent dielectric constant and relative equivalent magnetic permeability of metamaterials can be made to be positive, negative, or complex numbers less than 1, thereby fundamentally changing the propagation mode of electromagnetic waves.

The most common applications of metamaterials in the military industry are absorption and stealth. Due to the high impedance surface constructed by the negative electromagnetic parameters of metamaterials, thin plates can achieve electromagnetic wave absorption. Coupled with electromagnetic resonance structures (both magnetic and electrical resonance), the two can be independently designed to achieve impedance matching. Meanwhile,Metamaterial absorbing materialIt is narrowband absorbing and can solve low-frequency problems. If designed properly and coupled with the electromagnetic component of the incident electromagnetic wave, it can achieve 100% electromagnetic wave absorption within a specific frequency band. Simply put, metamaterials can achieve "negative refraction", where waves incident in all directions are completely diffracted and propagated in the metamaterial covering the target, propagating along the original direction without loss, achieving stealth effect.

Due to the potential threat of detection methods such as radar, infrared, laser, and visible light on battlefield weapons and equipment, there are many other coatings available, such as infrared stealth coatings, visible light stealth coatings, laser stealth coatings, sonar stealth coatings, and multifunctional stealth coatings. In recent years, nano coating materials have also been developedChiral absorbing materialConductive polymer materials, plasma stealth technology, etc. The development of multi band composite stealth materials has always been a key research direction for the country and military enterprises. How to make coatings compatible with each other in several bands will be one of the main research directions in the future.

Current situation and space of stealth material market

Stealth materials are still mainly used in weapons and equipment, and with the increasing emphasis on the role of drones in warfare, stealth capability has become one of the necessary characteristics, which is also one of the key core materials. It will continue to receive national policy support in the future.

In addition, stealth weapons may encounter coating changes, cracking, and delamination during daily use, transportation, and storage, requiring continuous maintenance and even recoating. They are a type of military consumable. Moreover, according to relevant information, the US F-117 needs to be recoated 9 out of 10 times, and even if it falls off and needs to be repaired, it needs to be recoated completely. Therefore, the cost of maintenance and new coating is the same, with a very large usage and high price, and a huge market space.

Although the market space is large, the industry has extremely high technological barriers, and military products have special characteristics and customized features. However, once it enters the market, the customer stickiness is very high and exclusive. Although there will be no foreign companies competing, it also indicates that the technology is confidential and cannot be used for technical reference.