Permanent magnet material characteristics
Permanent magnet materials are divided into: neodymium iron boron permanent magnet materials, ferrite permanent magnet materials, samarium cobalt permanent magnet materials, and alnico permanent magnet materials:
1. Neodymium iron boron permanent magnet material: Neodymium iron boron is the magnet with the highest performance currently found commercialized. It is called the magnet king and has extremely high magnetic properties. Its maximum magnetic energy product (BH) max is ferrite (Ferrite ) Is more than 10 times, and its own mechanical processing performance is also quite good, the maximum working temperature can reach 200 ℃. Moreover, its hard texture, stable performance, and good cost performance, so its application is extremely wide. But because of its strong chemical activity, the surface must be protected (such as Zn, Ni, electrophoresis, passivation, etc.).
2. Ferrite permanent magnet materials: The main raw materials of ferrite include BaFe12O19 and SrFe12019. Manufactured by ceramic technology, the texture is relatively hard and it is a brittle material. Due to the good temperature resistance, low price and moderate performance of ferrite magnet, it has become the most widely used permanent magnet.
3. Samarium cobalt permanent magnet material: According to the different composition, it is divided into SmCo5 and Sm2Co17. Due to the high price of samarium cobalt materials, its development is restricted. Samarium Cobalt Magnet SmCo, as a rare earth permanent magnet, has a high magnetic energy product (14-28MGOe), reliable coercivity and good temperature characteristics. Compared with neodymium iron boron magnets, samarium cobalt magnets are more suitable for working in high temperature environments.
4. Alnico permanent magnet material: Alnico is an alloy composed of aluminum, nickel, cobalt, iron and other trace metal elements. The casting process can be processed into different sizes and shapes, and the workability is very good. Cast AlNiCo permanent magnets have the lowest reversible temperature coefficient, and the operating temperature can be as high as 600 degrees Celsius. AlNiCo permanent magnet products are widely used in various instruments and other applications.
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