For samarium cobalt magnets Series 1-5 which is shortened as SmCo5, they have one atom of rare earth Samarium and five atoms of Cobalt. By weight this samarium cobalt magnet alloy will typically contain 36% Samarium with the balance Cobalt. The energy products of these samarium cobalt alloys range from 16 MGOe to 25 MGOe. These Samarium Cobalt magnets generally have a reversible temperature coefficient of -0.05%/°C. Saturation magnetization can be achieved with a moderate magnetizing field. This series of Samarium Cobalt magnet is easier to calibrate to a specific magnetic field than the SmCo 2-17 series magnets.
In the presence of a moderately strong magnetic field, unmagnetized magnets of this series will try to align its orietation axis to the magnetic field. Unmagnetized magnets of this series when exposed to moderately strong fields will get slightly magnetized. This can be an issue if post processing requires that the magnet be plated or coated. The slight field that the magnet picks up can attract debris during the plating or coating process causing for a potential plating or coating failure or a mechanically out of tolerance condition.
Machining or grinding this magnet by the user is discouraged. This material must be ground using diamond cutting and grinding tools and a significant amount of water based coolant. Dry ground powder can iqnite spontaneously with a small spark.
The coercivity is controlled by a process known as “nucleation”. S1665, S1865, S2064, S2065 and S2069 are Samarium Cobalt magnet alloys made from the Series 1-5 alloy.
For samarium cobalt magnets Series 2-17 which is shortened as Sm2Co17, they are an age hardening type with a composition of two atoms of rare earth Samarium Cobalt and 13-17 atoms of transition metals (TM). The TM content is rich in cobalt, but contains other elements such as iron and copper. Other elements like zirconium, hafnium and such may be added in small quantities to achieve better heat treatment response. By weight the alloy will generally contain 25% of Samarium. The maximum energy products of these alloys range from 20 MGOe to 32 MGOe. These alloys have the best reversible temperature coefficient of all rare earth alloys, typically being -0.03%/°C. The “second generation” Samarium Cobalt materials can also be used at higher temperatures. The most advanced Samarium Cobalt material offered by MCE is S3069 which has a guaranteed maximum energy product of 29.5 MGOe minimum. All the SmCo alloys with energy products that are 22 MGOe and higher that MCE offers are made from the Series 2-17 alloy.