Introduction to the influence of temperature on Alnico magnet

AlNiCo magnets have good temperature resistance, and their magnetic properties change minimally with temperature, making them ideal for temperature-sensitive applications. The reversible temperature coefficient of induction is -0.02%/℃, and the reversible temperature coefficient of internal coercivity It is +0.01%/℃. This makes Alnico the perfect choice for performance-critical applications such as medical and military. Temperature increase may cause a certain degree of permanent loss in the output of Alnico alloy, which depends on the physical shape of Alnico magnet and the shape of the BH curve. Above 530℃ may permanently change the metallurgical structure of Alnico. , Resulting in a significant permanent and irreversible decline in output. When the Alnico magnet may experience high temperature, it is recommended to heat the magnet to 10 degrees or higher than the expected maximum temperature to adjust the Alnico magnet, but in the future thermal cycling to a temperature lower than the adjusted temperature will not cause further permanent decrease in output ( The only change in the output will be the reversible loss, which disappears as the magnet cools, which is determined by the temperature coefficient of AlNiCo). It is recommended not to use Alnico magnets when the temperature is higher than 525 or 550°C (550°C or 1022°F or 823 Kelvin), otherwise it will cause permanent loss of magnetic output.
-75 degrees Celsius is considered to be a reasonably acceptable lower temperature for Alnico. Although about 10% of irreversible loss is reported at -190 degrees Celsius, the actual loss is a function of magnet geometry, total magnetic circuit and BH curve shape.