What is permanent magnetic material (hard magnetic material)

After being magnetized, the permanent magnetic material still retains its magnetism after removing the external magnetic field. Its performance is characterized by high remanence and high coercivity. This feature can be used to make permanent magnets, which can be used as a magnetic source. Such as common compasses, meters, micro-motors, motors, tape recorders, telephones and medical treatment. Permanent magnet materials include ferrite and metal permanent magnet materials.

Ferrites are used in large quantities, are widely used, and are low in price, but they have general magnetic properties and are used for permanent magnets generally required.

Among metal permanent magnet materials, high-carbon steel was first used, but its magnetic properties were poor. The varieties of high-performance permanent magnet materials include aluminum nickel cobalt (Al-Ni-Co) and iron chromium cobalt (Fe-Cr-Co); rare earth permanent magnets, such as the earlier rare earth cobalt (Re-Co) alloys (the main varieties are SmCo5 and Sm2Co17 made by powder metallurgy technology are widely used neodymium iron boron (Nd-Fe-B) rare earth permanent magnets, neodymium iron boron magnets not only have excellent performance, but also do not contain the rare element cobalt, so they become high-performance permanent magnet materials The representative of, has been used in high-performance speakers, electronic water meters, nuclear magnetic resonance meters, micro motors, automobile starting motors, etc.