1, The type of magnet
There are many types of magnets, which are generally divided into two categories: permanent magnets and soft magnetics.
Refers to permanent magnets, permanent magnets are divided into two categories:
The first major category is: metal alloy magnets including neodymium iron boron magnets (Nd2Fe14B), samarium cobalt magnets (SmCo),
AlNiCo magnet (ALNiCO)
The second major category is: ferrite permanent magnet material (Ferrite)
1. Neodymium magnet: It is the magnet with the highest commercialization performance. It is called magnetic king.
With extremely high magnetic properties, its maximum magnetic energy product (BHmax) is more than 10 times higher than that of ferrite. its
The machining performance itself is also quite good, working temperatures up to 200 degrees Celsius. And its texture is strong
Hard, stable performance, good cost performance, so its application is extremely extensive. But because of its strong chemical activity,
Therefore, it is necessary to treat its surface coating. (such as Zn, Ni, electrophoresis, passivation, etc.).
2. Ferrite magnet: Its main raw materials include BaFe 12 O 19 and SrFe 12 O 19 . Ceramic process
Made of hard texture, brittle material, due to the ferrite magnet has good temperature resistance, low price,
Moderate performance, has become the most widely used permanent magnet.
3. AlNiCo magnet: An alloy consisting of aluminum, nickel, cobalt, iron and other trace metals.
The casting process can be processed into different sizes and shapes, and the processability is very good. Cast aluminum-nickel-cobalt permanent magnet
With a minimum reversible temperature coefficient, the operating temperature can be as high as 600 degrees Celsius or more. AlNiCo permanent magnet products should be widely used
Used in a variety of instrumentation and other applications.
4. SmCo magnets : SmCo 5 and Sm2Co17 are classified according to their composition. 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 coercivity and good temperature characteristics. Compared with neodymium iron boron magnets, samarium cobalt
The magnet is more suitable for working in high temperature environments.