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 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 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.
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 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.