The application of permanent magnets in the aerospace and defense fields is very critical. Here are some specific application examples and advantages:

1. Navigation systems and guidance devices:Permanent magnets are used in the gyroscopes of launch vehicles to form a precisely adjusted stable magnetic field, which is essential for the rocket to accurately deliver the payload to the Earth's orbit. For example, the gyroscope of the Saturn V launch vehicle used rare earth permanent magnets.

2. Missile guidance:Rare earth materials play an important role in the guidance system of missiles. Whether it is radio frequency guidance, optical guidance or multi-mode composite guidance, rare earth materials are indispensable. Rare earth permanent magnets are used in circulators of radar microwave transmission systems and isolators of microwave receiving systems, usually made of nebium iron boron materials.

3. Optical and laser guidance:In optical guidance, rare earth materials are widely used, such as special glass used in TV guidance and camera lenses, which require the use of rare earth materials to improve specific performance. Laser guidance is completely based on rare earth materials. About 90% of the world's laser materials involve rare earths, among which the rare earth garnet system is the most widely used.

4. Rare earth permanent magnet motor:Rare earth permanent magnet motor has many advantages due to its high magnetic energy product, such as light weight, small size, high output power, good dynamic characteristics, high control accuracy, low energy consumption, high reliability, long life, wide operating temperature range, flexible shape, etc. It is particularly suitable for orbital spacecraft with harsh working environment and actuation systems that require reliable and precise control of movements.

5. Satellites and spacecraft:The deployment mechanisms and servo mechanisms of various equipment on satellites that provide energy, realize communication observation and telemetry functions all use rare earth permanent magnet motors as drives. For example, the deployment mechanism of the solar cell array of the Fengyun-3 meteorological satellite uses a samarium cobalt permanent magnet brushed DC motor; the antenna deployment mechanism of the Beidou navigation satellite uses a nephelium iron boron permanent magnet brushed DC motor.

6. Electromagnetic propulsion engine: In recent years, researchers have gradually applied electromagnetic propulsion engines on satellites and deep space probes, using rare earth permanent magnets to form magnetic fields.

7. Sensors: Many sensors used to monitor the working status of spacecraft and missiles also use rare earth permanent magnets to convert mechanical energy into electrical signals.

8. Improved stealth performance: Wave-absorbing rare earth materials are very beneficial to the improvement of missile stealth performance. This material has the characteristics of being very thin, light, wide absorption bandwidth, and strong absorption capacity. It has the potential to be used in stealth missiles in the future.

9. Rare earth magnesium alloy: Rare earth magnesium alloy has replaced aluminum alloy in the hatch and cover of spacecraft, greatly reducing the weight of the structure.

10. Titanium alloy investment casting: In the titanium alloy investment casting that is widely used in spacecraft and missile products, the yttrium oxide shell with rare earth components is not only stable in performance and low in price, but also has a high level in specific gravity, hardness and stability to titanium liquid.

Through the above application examples, we can see the importance of permanent magnetic materials in the aerospace and defense fields. They not only improve the performance of equipment, but also provide key support for achieving precise control and special functions.