What is the material of the magnet?

There are many types of magnets, generally divided into two categories: permanent magnets and soft magnets. The magnets we refer to generally refer to permanent magnets.

Permanent magnets are divided into two categories:

The first category is: metal alloy magnets including neodymium iron boron magnets (Nd2Fe14B), samarium cobalt magnets (SmCo), and alnico magnets (ALNiCO)

The second largest category is: ferrite permanent magnet materials (Ferrite)

1. NdFeB magnet: It is the magnet with the highest commercial performance currently found. It is called the magnet king and has extremely high magnetic properties. Its maximum magnetic energy product (BHmax) is more than 10 times higher than that of ferrite. Its own machining performance is also quite good. The operating temperature can reach up to 200 degrees Celsius. Moreover, its texture is hard, its performance is stable, and it has good cost performance, so it is widely used. However, because of its strong chemical activity, its surface must be treated with a coating. (Such as Zn, Ni plating, electrophoresis, passivation, etc.).

2. Ferrite magnet: Its main raw materials include BaFe12O19 and SrFe12O19. Made through ceramic technology, the texture is relatively hard and brittle. Because ferrite magnets have good temperature resistance, low price, and moderate performance, they have become the most widely used permanent magnets.

3. Alnico magnet: It 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 machinability is very good. Cast AlNiCo permanent magnets have the lowest reversible temperature coefficient and the operating temperature can be as high as over 600 degrees Celsius. Alnico permanent magnet products are widely used in various instrumentation and other application fields.

4. Samarium cobalt (SmCo) is divided into SmCo5 and Sm2Co17 according to different ingredients. Its development is limited due to the high price of its materials. Samarium cobalt (SmCo), as a rare earth permanent magnet, not only has a high magnetic energy product (14-28MGOe), reliable coercive force and good temperature characteristics. Compared with NdFeB magnets, SmCo magnets are more suitable for working in high temperature environments.