Many types of magnets, generally divided into permanent magnet and
soft magnetic two categories, we say the magnet, generally refers to the
permanent magnet Permanent magnet is divided into two categories: The first category is: metal alloy magnets include NdFeB magnets
Nd2Fe14B), samarium cobalt magnets (SmCo), Alnico magnets (ALNiCO) The second category is: ferrite permanent magnet material (Ferrite) 1,
NdFeB magnets: It is currently found the highest commercial performance
of the magnet, known as the magnetic king, has a high magnetic
properties of its maximum energy product (BHmax) higher than Ferrite
(Ferrite) more than 10 times. Its own mechanical processing performance is also quite good. Working temperature up to 200 ℃. And its texture is hard, stable performance, a very good price, so its application is extremely extensive. But because of its strong chemical activity, it must be its surface coating treatment. (Such as plating Zn, Ni, electrophoresis, passivation, etc.). Ferrite magnets: Its main raw materials include BaFe12O19 and SrFe12O19. Made by the ceramic process, the texture is relatively hard, brittle
material, as the ferrite magnets have good temperature resistance, low
cost, moderate performance, has become the most widely used permanent
magnet. 3. Alnico magnets: aluminum, nickel, cobalt, iron and other trace metals constitute an alloy. Casting process can be processed into different sizes and shapes, workability is good. Aluminum-nickel-cobalt
cast permanent magnet has the lowest reversible temperature
coefficient, the working temperature can be as high as 600 ℃. Alnico permanent magnet products are widely used in various instrumentation and other applications. 4, Samarium Cobalt (SmCo) According to the different ingredients into SmCo5 and Sm2Co17. Its material development is limited by the high cost of its materials. Samarium
cobalt (SmCo) as a rare earth permanent magnet, not only has a higher
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 environment.