SmCo Magnet's Composition, Series and Types

Samarium cobalt magnet is a type of rare-earth magnet mainly composed of samarium–cobalt alloys. A SmCo magnet may have a magnetic strength comparable to that of a NdFeB magnet but is higher in temperature rating and coercivity. SmCo magnets are available in two series defined by the ratio of Samarium to Cobalt: Series1-5 (SmCo5) and Series 2-17 (Sm2Co17). And there are currently in the magnet market two types of SmCo magnets are available: the bonded type and the sintered type.

SmCo5

SmCo5 magnets are composed of Samarium-Cobalt alloys with Sm-Co ratio of 1-5, that is to say, one atom of Samarium with five atoms of Cobalt. By weight, the Samarium would occupy 36% of the total. By weight, this samarium cobalt magnet alloy will typically contain 36% Samarium with the balance Cobalt. This series of SmCo magnet is able to provide Max. Energy Product of 25 MGOe and has a reversible temperature coefficient of -0.05%/°C. In addition, this series is easier to calibrate to a specific magnetic field than the Sm₂Co₁₇ series.

Sm2Co17

Sm2Co17 magnet is composed of Samarium-Cobalt alloys with SmCo ratio of 2 to 17, that is to say, 2 Samarium atoms with 17 Cobalt atoms. It also contains other elements such as iron, copper, Zirconium, Hafnium but in very small quantities. By weight the Samarium occupies about 25% of the total. This type has a higher Max. Energy Product of 32 MGOe and a reversible temperature coefficient of -0.03%/°C.

Bonded SmCo magnets

The bonded SmCo magnets are anisotropic ones manufactured with magnet powder held in place by epoxy resins or other special “binders”. Energy products of the bonded magnet range from 5 MGOe to 15.1 MGOe.

Sintered SmCo magnets

Sintered SmCo magnets are generally manufactured through this process: alloy milling to fine powder-powder pressed-magnetic fields applying-sintering in special furnace-grounding and shaping-coating. Thank you for reading our article and we hope it can help you to have a better understanding of the SmCo magnet. If you want to know more about samarium cobalt magnets and other magnet products, we advise you to visit Stanford Magnets for more information.