Structural absorbing material is a kind of multi-functional reinforced plastic. It can not only bear the weight and high strength of composite material as a structural part, but also absorb or transmit electromagnetic waves. It has received extensive attention and research since the Second World War. , And began to be applied, and now it has become an important development direction of contemporary stealth materials, and is highly valued by researchers at home and abroad.
① Carbon-carbon reinforced plastic. The carbon-carbon reinforced plastic developed by Williams International Corporation is suitable for high-temperature parts, and it can well suppress infrared radiation and absorb radar waves. The dense carbon foam layer is used in the engine part to absorb the heat radiation of the engine exhaust, and it can also be made into the leading edge of the wing, the nose and the tail.
②Glass fiber reinforced plastic containing ferrite. This material is light, strong and rigid. Japan has equipped it on the tail of an air-to-ship missile (ASM1), and its wings will also be modified with this material to greatly improve its stealth performance.
③Reinforced plastic filled with graphite. The United States has made great progress in the development of graphite thermoplastic reinforced plastics and graphite epoxy resin reinforced plastics. These materials still maintain toughness at low temperatures.
④Glass fiber reinforced plastic. This kind of Fibalog is made by adding glass fiber to plastic. This material is harder and can be used as aircraft skin and some internal components without adding metal reinforcing ribs. It has good radar wave absorption characteristics. .
⑤ Carbon fiber reinforced plastic. The carbon fiber reinforced plastic developed by the US Air Force Materials Laboratory can absorb radiant heat without reflecting radiant heat, which can reduce the characteristics of radar waves and infrared rays, and can be made with it.
⑥Silicon carbide fiber, silicon carbide-carbon fiber (SiC-C) reinforced plastic. Silicon carbide fiber contains silicon c as the engine compartment skin, the leading edge of the wing and the front section of the fuselage. It not only has good absorption characteristics, but also can weaken the infrared signal of the engine, but also has high temperature resistance, low relative density, good toughness, high strength, and electrical resistance. The advantages of high rate are one of the rapidly developing absorbing materials abroad, but there are still some problems, such as too high resistivity. By artificially designing carbon and silicon carbide in different proportions and controlling their resistivity, they can be made into SiCC composite fibers, SCC composite fibers and epoxy that are resistant to high temperature, oxidation, and have excellent mechanical properties and good microwave absorption properties. Reinforced plastic made of resin. It is a structural material composed of SiCC fiber, grafted imide group and epoxy resin copolymerized and modified into a matrix, which has excellent microwave absorbing properties.
⑦Mixed fiber reinforced reinforced plastics. Hybrid fiber-reinforced reinforced plastic is a reinforced plastic that is manufactured by increasing the mixing ratio between the fibers and the structural design form, meeting special performance requirements or having better comprehensive performance. Hybrid fiber-reinforced plastics with good wave absorbing properties have been manufactured, which are widely used in aircraft manufacturing.
⑧Special carbon fiber reinforced carbon thermoplastic resin-based reinforced plastic. This material has excellent absorbing properties and can greatly attenuate pulses with a frequency of 0.1MHz-50GHz. It has now been used in the fuselage and wings of Advanced Fighters (ATF), and its model is APC (HTX). In addition, APC2 is a unidirectional reinforced grade of Celion4000 carbon fiber and PEEK multifilament hybrid yarn, which is especially suitable for manufacturing helicopter rotors and missile shells. The US stealth helicopter LHX has already adopted this reinforced plastic.
⑨ Conductive reinforced plastic. Conductive reinforced plastics are made by adding conductive fibers, thin skins or nano-scale metal powder to non-metallic polymers or resins. When the radar wave penetrates, because part of the energy is absorbed, the reflected radar wave energy is greatly attenuated, so it becomes an effective stealth material, and its absorption frequency band can be adjusted by the type and amount of substances added. The mixed materials include polyacrylonitrile fiber, nickel-plated carbon fiber, stainless steel fiber, thin slices and ferrite, nickel, cobalt powder, etc. This composite material can be used as a structural material for aircraft or missiles.