What are rare earth permanent magnets, and rare earth permanent magnets include those categories
Many people are not very clear about rare earth magnets, so today Xiaofu, a magnet manufacturer who has taken courage, shares with you what are rare earth magnets? Classification and application of rare earth magnets.
What are rare earth magnets?
As the name suggests, a rare earth magnet is a type of magnet that includes rare earth metals. The rare earth metal family has 17 members, including La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc. Rare earth metals Pr, Nd, Dy are used as raw materials for NdFeB, and Sm is used as raw materials for sa cobalt.
Rare earth metal is very expensive because it is a rare resource. It also causes environmental damage during mining. As a result, some countries such as the United States, Russia and Australia stopped mining and bought cheap rare earth materials or products from China. The fluctuation of rare earth metal prices is an important factor for the price increase of rare earth magnets.
The chemistry of rare earth magnets is based on the intermetallic compound Nd2Fe14B. Magnets have high energy product and coercivity. At the same time, the advantages of high energy density make rare earth permanent magnets widely used in modern industry and electronic technology, making it possible to miniaturize, lighten and thin the equipment.
Rare earth magnets are mainly NdFeB and SmCo.
1. NdFeB magnets
Sintered NdFeB magnets are the most powerful and cost-effective magnets in the world. It is widely used in computers, electric motors, wind turbines, electric vehicles, instrumentation, magnetic drive bearings, hi-fi speakers, nuclear magnetic resonance (NMR) imaging and aerospace navigators. It also plays an important role in new technologies such as maglev trains. Inexpensive Pr-Nd metal replaces pure Nd to improve its oxidation resistance and mechanical properties. Dy is an additive for high-grade NdFeB magnets. Adding only 2-3% Dy can improve the magnet coercivity. As the demand for magnets in high-end products increases, so does the demand for Dy.
2. Samarium Cobalt Magnet
Samarium Cobalt is the first rare earth magnet in the industry, including SmCo5 and Sm2Co17. But currently Sm2Co17 is the material of choice. The oxide oxide used in samarium cobalt magnets is not very pure. From cost considerations, 95% oxidized sa product is sufficient.
Main applications of rare earth magnets;
Rare earths are mainly used in micro motors, permanent magnet instruments, electronics industry, automobile industry, smart home, nuclear magnetic resonance equipment, sensors, audio equipment, magnetic levitation systems, magnetic transmission mechanisms and magnetic therapy equipment, etc. Widely used in computer, magnetic machinery, automatic control, microwave communication, aerospace, medical equipment and other fields. use.
