Magnets classification

Magnets can be grouped into "permanent magnet" and "non permanent magnets." The permanent magnet may be natural products, also known as natural magnet can also be manufactured by hand (the strongest magnets are neodymium magnets). The permanent magnet, and only in certain conditions be magnetic, usually produced in the form electromagnet, which is to strengthen the magnetic field by the current.

Concept
Soft including silicon Grate Magnets and soft core; hard magnetic including Alnico, SmCo, ferrite and neodymium, of which, the most expensive is samarium cobalt magnet, the cheapest is ferrite magnet, NdFeB magnets are the highest performance, but the most stable performance, the temperature coefficient is the best alnico, the user can choose according to the different needs of different hard magnetic products.

We said magnet, generally refers to permanent magnets.

Permanent magnet is divided into two major categories.

The first category
Metal alloy magnets including NdFeB magnet Nd2Fe14B), samarium cobalt magnets (SmCo), Alnico magnet (ALNiCO)

The second category
Ferrite permanent magnet material (Ferrite)

1. It is found in NdFeB magnets commercialization highest performance magnets, known as Magneto, with a high magnetic its maximum energy product (BHmax) higher than ferrite (Ferrite) 10 times or more. Its own machining performance is also quite good. Operating temperature up to 200 degrees Celsius. And its hard texture, stable performance, good price, so its application is extremely broad. But because of its chemical activity is very strong, it must be on its surface coating. (Eg plating Zn, Ni, electrophoresis, and passivation).

2. It is the main raw materials include ferrite magnets BaFe12O19 and SrFe12O19. By law made of ceramic, texture rather hard, is a brittle material, due to ferrite magnets have good temperature resistance, low price, moderate performance, has become the most widely used permanent magnets.

3. Alnico magnet is made of aluminum, nickel, cobalt, iron and other trace metal elements in an alloy. Casting process can be processed into different sizes and shapes, workability is very good. Cast Alnico magnet has the lowest reversible temperature coefficient, operating temperature up to 600 degrees Celsius. Alnico products are widely used in a variety of instruments and other applications.

4. Samarium cobalt (SmCo) overband magnetic separator divided according to different ingredients SmCo5 and Sm2Co17. Because the material is expensive and their development is limited. Samarium cobalt (SmCo) as a rare earth permanent magnet, not only has a high energy product (14-28MGOe), coercivity reliable and good temperature characteristics. Compared with NdFeB magnets, SmCo magnet is more suitable for working in a hot environment.