How does temperature affect Alnico magnets

Alnico magnets are popular and commonly used in many applications because of their exceptional stability when operating at high temperatures. Their output changes least when operating at high temperatures when compared to other types of magnet such as ferrite/ceramic magnets, or rare-earth magnets. However, regular increasing temperatures can lead to some loss of magnetism but this very much depends on the shape and size of the magnet. Their resistance to temperate makes them a popular choice for aerospace, automotive and military applications.

Despite the resistance to temperature displayed by Alnico magnets they are susceptible to demagnetising forces such as external magnetic fields.

Any of the Alnico magnet grades commercially available can operate in temperatures between 400ºC and 450ºC, some of the higher grades can even operate in temperatures as high as 550ºC, meaning they are the only suitable option for applications with an operating temperature about 350ºC.

Did you know?
Alnico magnets can continue to be effective, event when heated to the point of glowing red-hot!

Alnico magnets are also generally good performers in low temperatures down to approximately -70 ºC -100 ºC.

Some grades actually increase their resistance to demagnetisation as they get hotter by small amounts from ambient temperature.

 

MAGNET GRADE

Max. Working Temperature
(based on High working point)

Cast Alnico 2450 ºC = 842 ºF
Sintered Alnico 2450 ºC = 842 ºF
Cast Alnico 3450 ºC = 842 ºF
Sintered Alnico 3450 ºC = 842 ºF
Cast Alnico 5525ºC = 977 ºF
Sintered Alnico 5525ºC = 977 ºF
Cast Alnico 6525ºC = 977 ºF
Sintered Alnico 6525ºC = 977 ºF
Cast Alnico 5DG525ºC = 977 ºF
Cast Alnico 5-7525ºC = 977 ºF
Cast Alnico 8555ºC = 1022 ºF
Sintered Alnico 8555ºC = 1022 ºF
Cast Alnico 8HC555ºC = 1022 ºF
Sintered Alnico 8HC555ºC = 1022 ºF
Cast Alnico 9555ºC = 1022 ºF
Sintered Alnico 9555ºC = 1022 ºF
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