Is Cobalt A Permanent Magnet?

The answer is YES.

Samarium cobalt magnet is one of the rare earth permanent magnets. It includes SmCo5 (1:5), and Sm2Co17 (2:17).

Compared with neodymium magnets, the biggest feature of samarium cobalt magnets is that it has superior anti-corrosive and oxidation resistance. So they don’t need any coating.

samarium cobalt magnet

Due to excellent properties, we can hardly see any SmCo magnet in daily supplies. They are mainly for use in aerospace, national defense, microwave devices, communication, medical equipment, instruments, and meters, all kinds of the magnetic transmission device, sensor, magnetic processor, and motor, magnetic crane.

The BH(max.) ranges from 16 MGOe to 32 MGOe. So it is the only one type of rare earth magnet that can be close to low grade sintered neodymium magnet.

Meanwhile, the high-temperature resistance of SmCo magnet is from 250℃ to 350℃, the Curie temperature is from 700℃ to 840℃. That’s what makes the SmCo magnet different – high magnetic property, high working temperature.

But if you need a coating for nice appearance or enhance anti-corrosive performance, they can be plated with nickel, zinc, gold, or epoxy or other coatings.
In regard to SmCo magnet application, they are used chiefly in the very complex working environment because of good magnetic stability. So they are very suitable for manufacturing various high-performance permanent magnet motor.

Generally, according to the size and shape of the finished product, the manufacturer sinters the block blank and then uses the diamond blade to cut into the finished product size. Because samarium cobalt is conductive, it can be processed by wire cutting. In theory, samarium and cobalt can be cut into shapes that can be cut by wire cutting, without considering magnetization and larger size.

Samarium cobalt magnet, corrosion resistance is good, generally, do not need to carry out anti-corrosion plating or coating. In addition, the texture of the cobalt magnet is very brittle, so it is difficult to process small size or thin-walled products.

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