In the era of rapid development of modern electronic technology, the electromagnetic environment is becoming increasingly complex, and the problems brought about by electromagnetic interference (EMI) and electromagnetic radiation are becoming more and more serious. From the mutual interference of electronic devices, to the potential threats to human health, and then to the stealth requirements of targets in the military field, it is urgent to solve electromagnetic problems. As an efficient microwave – absorbing material, flake – shaped iron – silicon – chromium microwave – absorbing powder emerges as the times require and becomes a key material to address electromagnetic challenges, playing an indispensable role in many fields.
I. Basic Principle of Flake – shaped Iron – Silicon – Chromium Microwave – Absorbing Powder
The working principle of microwave – absorbing materials is based on the absorption and loss of electromagnetic waves by the materials. When electromagnetic waves are incident on the surface of a microwave – absorbing material, a part is reflected, a part is absorbed, and a part is transmitted through the material. An ideal microwave – absorbing material should minimize reflection and convert most of the electromagnetic wave energy into other forms of energy (such as heat energy) and dissipate it.
The microwave – absorbing mechanism of flake – shaped iron – silicon – chromium microwave – absorbing powder mainly includes magnetic loss and dielectric loss. From the perspective of magnetic loss, the iron – silicon – chromium alloy has a relatively high magnetic permeability. Under the action of an alternating magnetic field, the magnetic domains inside the material will repeatedly turn and the domain walls will move. This process will generate hysteresis loss and convert electromagnetic energy into heat energy. At the same time, due to the limited electrical conductivity of the material, an induced current will be generated under the action of electromagnetic waves. When the current flows inside the material, Joule heat will be generated due to resistance, which is the dielectric loss. The flake – shaped structure design further optimizes the microwave – absorbing performance, increases the interaction area between the material and electromagnetic waves, and prolongs the propagation path of electromagnetic waves inside the material, thus enhancing the absorption effect of electromagnetic waves.
II. Performance Characteristics
(I) High Microwave – Absorbing Performance
Flake – shaped iron – silicon – chromium microwave – absorbing powder exhibits excellent microwave – absorbing ability in a relatively wide frequency range. Generally, in the commonly used microwave frequency bands such as the X – band (8 – 12GHz) and Ku – band (12 – 18GHz), its reflection loss can reach below – 20dB, and even reach – 40dB under certain specific conditions. This means that most of the incident electromagnetic waves are effectively absorbed, and very little electromagnetic waves are reflected back into space. This high microwave – absorbing performance makes it perform well in application scenarios with strict requirements for microwave absorption, such as military stealth equipment and high – performance electronic equipment electromagnetic shielding.
(II) Low Thickness Requirement
In practical applications, the thickness of the microwave – absorbing material is an important consideration. Flake – shaped iron – silicon – chromium microwave – absorbing powder, with its unique flake – shaped structure and excellent microwave – absorbing performance, can achieve good microwave – absorbing effects at a relatively low thickness. Usually, coating or filling a composite material containing this microwave – absorbing powder with a thickness of only a few millimeters can meet the microwave – absorbing requirements of most conventional applications. Compared with some other microwave – absorbing materials, this low – thickness requirement not only reduces the weight of the product but also saves space, providing convenience for the miniaturization and lightweight design of products. It has significant advantages in fields such as aerospace and portable electronic devices.
(III) Strong Oxidation Resistance
The iron – silicon – chromium alloy itself has a certain oxidation resistance. After special process treatment, the oxidation resistance of the flake – shaped iron – silicon – chromium microwave – absorbing powder is further enhanced. Under different environmental conditions, such as high temperature and humidity, it can maintain stable physical and chemical properties for a long time and will not cause a decline in microwave – absorbing performance due to oxidation. This makes the microwave – absorbing materials based on this microwave – absorbing powder have a longer service life and reliability in application scenarios such as outdoor equipment and harsh industrial environments, reducing maintenance costs and replacement frequencies.
(IV) Good Compatibility
Flake – shaped iron – silicon – chromium microwave – absorbing powder can be well – compatible with a variety of matrix materials, such as epoxy resin, polyurethane, rubber and other polymer materials, as well as aluminum alloy, magnesium alloy and other metal materials. By compounding with these matrix materials, microwave – absorbing composite materials that meet different application requirements can be prepared, such as microwave – absorbing coatings, microwave – absorbing patches, microwave – absorbing structural parts, etc. This good compatibility provides a strong guarantee for its wide application in different fields. According to specific use environments and performance requirements, suitable matrix materials can be flexibly selected to prepare microwave – absorbing products.
III. Application Scenarios
(I) Military Field
Stealth Fighters: In modern warfare, stealth technology is the key to enhancing the survivability and combat effectiveness of fighter jets. Flake – shaped iron – silicon – chromium microwave – absorbing powder is widely used in the microwave – absorbing coatings of the fuselage, wings, tails and other parts of stealth fighters. By absorbing the electromagnetic waves emitted by enemy radars, the radar cross – section (RCS) of the fighter jet is reduced, making the fighter jet difficult to be detected on the radar screen, thus achieving a stealth effect and improving the fighter jet’s penetration ability and survival probability in air combat. For example, the F – 35 fighter jet of the United States adopts advanced microwave – absorbing material technology, in which flake – shaped iron – silicon – chromium microwave – absorbing powder plays an important role in its microwave – absorbing coating system.
Stealth Ships: For naval ships, reducing their own electromagnetic signal characteristics is also of great significance. Adding flake – shaped iron – silicon – chromium microwave – absorbing powder to the microwave – absorbing materials of the superstructure, masts, hull surfaces and other parts of the ship can effectively reduce the reflection of the ship to radar waves, communication waves and other electromagnetic waves, reduce the detection distance by the enemy’s detection system, and improve the stealth performance and battlefield survivability of the ship. At the same time, the microwave – absorbing material can also reduce the electromagnetic interference between the ship’s internal electronic devices and ensure the normal operation of the ship’s electronic system.
Stealth Missiles: As an important strike weapon in modern warfare, the stealth performance of missiles directly affects the combat effectiveness. Coating the missile body surface with a microwave – absorbing material containing flake – shaped iron – silicon – chromium microwave – absorbing powder can reduce the radar reflection signal of the missile during flight, increase the difficulty of enemy interception, and improve the hit rate and penetration ability of the missile. In addition, for some cruise missiles, the microwave – absorbing material can also reduce the infrared signal generated by the engine exhaust flame, achieve infrared stealth, and further improve the comprehensive stealth performance of the missile.
(II) Electronic Equipment Field
Electromagnetic Shielding: With the increasing integration of electronic devices, the problem of electromagnetic interference inside electronic devices is becoming more and more serious. Flake – shaped iron – silicon – chromium microwave – absorbing powder can be used to prepare electromagnetic shielding materials for electronic devices, such as shielding covers, shielding sheets, etc. Applying these shielding materials to mobile phones, computers, tablets and other electronic devices can effectively absorb and shield the electromagnetic interference generated between different components inside the device, ensure the normal operation of the device, and improve the stability and reliability of the device. At the same time, for some electronic devices with high requirements for the electromagnetic environment, such as medical electronic devices and precision testing instruments, the shielding materials made of flake – shaped iron – silicon – chromium microwave – absorbing powder can also prevent the influence of external electromagnetic interference on the device and ensure the accuracy of the device’s measurement and diagnostic results.
Microwave – Absorbing Patches: In some high – frequency circuits, such as microwave circuits and radio – frequency circuits, in order to reduce signal reflection and transmission loss, microwave – absorbing patches are needed to absorb the excess electromagnetic wave energy. The microwave – absorbing patches made of flake – shaped iron – silicon – chromium microwave – absorbing powder have good microwave – absorbing performance and dimensional stability, and can be accurately attached to the surface of circuit components, effectively absorbing the stray electromagnetic waves generated in the circuit, and improving the signal transmission quality and efficiency of the circuit. In addition, the microwave – absorbing patches can also be used to improve the radiation performance of the antenna, reduce the sidelobe radiation and back – radiation of the antenna, and improve the directivity and gain of the antenna.
(III) Communication Field
Base Station Antennas: In mobile communication base stations, base station antennas are key components for signal transmission and reception. With the popularization of 5G communication technology, base station antennas face a more complex electromagnetic environment and higher performance requirements. Applying flake – shaped iron – silicon – chromium microwave – absorbing powder to the radiation units and reflector plates of base station antennas can effectively reduce the electromagnetic interference between antennas, reduce signal reflection and scattering, and improve the radiation efficiency and signal coverage of the antennas. At the same time, the microwave – absorbing material can also improve the polarization characteristics of the base station antennas and enhance the anti – interference ability and communication quality of the communication system.
Satellite Communication: In the satellite communication system, the communication between the satellite and the ground station needs to be realized through high – gain antennas. Since the satellite is in a complex space electromagnetic environment and is easily affected by various electromagnetic interferences, the electromagnetic protection requirements for satellite antennas are extremely high. The microwave – absorbing materials made of flake – shaped iron – silicon – chromium microwave – absorbing powder can be used for the shielding and protection of satellite antennas, absorbing various electromagnetic radiations and interference signals from space, and ensuring the stable and reliable satellite communication. In addition, the microwave – absorbing material can also reduce the weight of the satellite, reduce the launch cost, and improve the effective payload capacity of the satellite.
(IV) Automotive Field
Automotive Electronic Systems: Modern automobiles are equipped with a large number of electronic devices, such as engine control systems, in – vehicle communication systems, and automatic driving assistance systems. These electronic devices will generate electromagnetic interference during operation and are also easily affected by external electromagnetic interference. Applying flake – shaped iron – silicon – chromium microwave – absorbing powder to the shielding materials of automotive electronic systems can effectively reduce the electromagnetic interference between electronic devices, improve the reliability and stability of the automotive electronic system, and ensure the safe driving of the vehicle. For example, using microwave – absorbing materials on the outer shell of the engine control unit (ECU) and around the in – vehicle antenna can reduce the impact of electromagnetic interference on these key components.
Automotive Radars: Automotive radars are an important part of autonomous driving technology, such as millimeter – wave radars used for vehicle ranging, speed measurement, and target recognition. Flake – shaped iron – silicon – chromium microwave – absorbing powder can be used for the antenna cover and electromagnetic shielding of automotive radars, reducing radar signal reflection and interference, and improving the detection accuracy and reliability of the radar. In a complex traffic environment, good microwave – absorbing materials can help automotive radars more accurately sense surrounding vehicles and obstacles, providing reliable data support for autonomous driving.
Flake – shaped iron – silicon – chromium microwave – absorbing powder, with its unique performance characteristics, shows great application potential and value in many fields such as military, electronic equipment, communication, and automotive. With the continuous progress of science and technology and the increasing requirements for the electromagnetic environment, the research and development of flake – shaped iron – silicon – chromium microwave – absorbing powder will also continue to deepen, its performance will be further improved, and its application scope will continue to expand. It will provide more effective solutions to various electromagnetic problems and promote the technological development and innovation of related fields.