How to choose the appropriate magnet according to the working temperature?

Working temperature (Tw) refers to the temperature range that the magnet can withstand in practical applications. Different substances have different operating temperatures due to their different thermal stability. The maximum operating temperature of magnetic steel is much lower than the Curie temperature. Within the operating temperature, the magnetic force will decrease as the temperature increases, but most of it can be restored after cooling.

The relationship between working temperature and Curie temperature: the higher the Curie temperature, the higher the working temperature of magnetic materials, and the better the temperature stability. Adding elements such as cobalt, terbium, and dysprosium to sintered NdFeB raw materials can increase its Curie temperature. Therefore, high coercivity products (H, SH,...) generally contain added dysprosium.

Different grades of the same magnet have different temperature resistance due to different compositions and structures. Taking NdFeB as an example, the maximum operating temperature of different series of magnets ranges from 80°C to 230°C.