The Difference between Maximum Working Temperature and the Curie Temperature

Magnet consumers are often confused the definitions of Max. Working Temperature Tw and the Curie Temperature Tw of the permanent magnet. In reality, Max. Working Temperature and the Curie Temperature Tc are two totally different conceptions.

Magnetism behavior of material can be classified into ferromagnetism, ferritemagnetism, anti-ferromagnetism, paramagnetism, and diamagnetism, then permanent magnet is definitely belongs to the ferromagnetc material. For ferromagnetic material, thermal oscillation of internal elementary particles will be aggravated with increasing temperature, then alignment of micro magnetic dipole moment inside the permanent magnetic material gradually disorder. Thereby, magnetic polarization J declines with increasing temperature in macroscopic. Magnetic polarization J will further drop to zero once the temperature exceeds a certain temperature, then permanent magnetic material transforms into paraferromagnetism state and basically lost their magnetism. The transition temperature between ferromagnetism and paramagnetism is generally known as Curie Temperature or Curie point.

Max. Working Temperature, also referred as the Max. Operating Temperature, is a specific temperature that magnetic performance of permanent magnetic material reduces a certain extent in comparison with room temperature. Max. Working Temperature of the permanent magnet is considerably lower than its Curie Temperature. Take sintered Neodymium magnet as an example, either Max. Working Temperature or Curie Temperature can be significantly enhanced by adding Cobalt (Co), Gallium (Ga), and heavy rare earth elements Dysprosium (Dy) or Terbium (Tb). Beside Curie Temperature, Max. Working Temperature of every permanent magnetic material is also influenced by its intrinsic coercivity, working status in the magnetic circuit. The same magnet has completely different Max. Working Temperature under different applications.