[Common knowledge about high temperature resistance of magnets]

Many people who buy magnets from companies have a vague concept of the use temperature of magnets. Of course, this problem cannot be explained in a few words. It involves quantum mechanics, thermodynamics, solid mechanics and other aspects. If they are shown the company's table, they still feel unintuitive. I have referred to a lot of information at home and abroad. Maybe it's because the scope of this issue is too large and I can't fully understand it, but I still want to talk about my personal humble opinion.

Permanent magnet factories like to say that their magnets will never demagnetize, but everything in the world has a moving side, and non-demagnetized permanent magnets do not exist. There are many reasons for demagnetization, but the internal reason is mainly the internal molecular thermal motion of the internal magnet. Thermal motion can change the direction of the magnetic pole and even cause the magnet to disintegrate, and the magnet has no magnetism at all. The temperature of magnetic disintegration is the internal point, which is generally expressed by TC. The ferrite in the magnets sold by our company is about 450℃, AlNiCo is about 860℃, NdFeB is 320℃-380℃, and barium cobalt is 450℃-840℃. The height of the internal point is related to the crystal structure formed by the sintering of the magnet, impurities, cooling environment, alloy composition ratio, and specific sintering process (composition melting ingot, powder pressure type, sintering tempering magnetic detection, grinding, pin cutting, and electroplating finished products).

The indoor temperature of common magnets is about 450℃, NdFeB magnets are 320-380℃, and AlNiCo magnets are 860-900℃.

Working temperature: 80~100℃ for ferrite magnets, high temperature resistant models can reach 350℃, 60~200℃, 250~350℃, and AlNiCo magnets are 450~900℃.