SmCo Disc Magnet

Samarium Cobalt Magnet

A samarium cobalt magnet is a type of rare earth magnet. It is made from a combination of samarium, cobalt, and other rare earth metals through a process of proportioning, melting into an alloy, crushing, pressing, and sintering. This material has a high magnetic energy product and an extremely low temperature coefficient. The maximum working temperature can reach 350°C, and there is no limit on the negative temperature. When the working temperature exceeds 180°C, its maximum magnetic energy product (BHmax), coercivity, temperature stability, and chemical stability all surpass those of NdFeB permanent magnet materials. It also has strong resistance to corrosion and oxidation, making it widely used in aerospace, national defense, microwave devices, communications, medical equipment, instruments, meters, various magnetic transmission devices, sensors, magnetic processors, motors, magnetic cranes, and more.

The maximum magnetic energy product (BHmax) of samarium cobalt magnets ranges from 16 MGOe to 32 MGOe, with a theoretical limit of 34 MGOe. There are two composition ratios for samarium cobalt magnets: 1:5 and 2:17 (samarium atoms to cobalt atoms).

SmCo Disc Magnet Processing process

The production process includes: batching → smelting to create ingots → powder making → pressing → sintering and tempering → magnetic testing → grinding → precision processing → finished product.

These alloys are usually machined in an unmagnetized state. Samarium cobalt is processed using wet fine grinding (with water-cooling for heat dissipation) and diamond grinding wheels. This procedure is necessary when drilling holes or addressing other functional requirements. The grinding waste must not be allowed to completely dry, as samarium cobalt has a low flash point. A small spark, such as one produced by static electricity, can ignite it easily. The resulting fire can generate very high temperatures and is difficult to control.

Hazards

1. SmCo magnets are prone to chipping, so goggles must be worn when handling them.
2. Allowing the magnets to collide can cause them to shatter, creating potential hazards.
3. Samarium cobalt magnets are produced through a sintering process, which can result in internal cracks. These magnets lack mechanical integrity and only serve to generate a magnetic field. Therefore, special mechanical systems must be designed to ensure adequate mechanical reliability for the overall system.

Attributes

1. Very high coercivity.
2. Excellent temperature stability (maximum operating temperature ranges from 250°C to 550°C, and the Curie temperature ranges from 700°C to 800°C).
3. Expensive and susceptible to price fluctuations (the cobalt market is highly price-sensitive).

physical parameters