These samarium cobalt magnet alloys 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.
|total||13 sintered samarium cobalt magnets SM2CO17|
|parameter||remanence||Coercive force||intrinsic coercivity||maximum energy product||density||pressure ring strength|
|total||4 bonded samarium cobalt magnets SmCo magnets|
|Typical Physical Properties - Type 1:5|
|Curie Temperature||720 - 750°C|
|Coefficient of Thermal Expansion - Perpendicular||+12.0 - +13.0 x 10-6 °C-1|
|Coefficient of Thermal Expansion - Parallel||+6.0 - +7.0 x 10-6 °C-1|
|Electrical Resistivity||50 - 60 µΩ·cm|
|Density||8.2 - 8.3 g·cm-3|
|Vicker's Hardness||550 - 650 HV|
|Young's Modulus||100 - 110 kN·mm-2|
|Bending Strength||0.12 - 0.18 kN·mm-2|
|Compressive Strength||0.9 - 1.0 kN·mm-2|
|total||9 samarium cobalt magnets SM1CO5|
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.
|Typical Physical Properties - Type 2:17|
|Curie Temperature||800 - 825°C|
|Coefficient of Thermal Expansion - Perpendicular||+11.0 - +12.0 x 10-6 °C-1|
|*Coefficient of Thermal Expansion - Parallel||+9.0 - +10.0 x 10-6 °C-1|
|Electrical Resistivity||80 - 90 µΩ·cm|
|Density||8.3 - 8.4 g·cm-3|
|Vicker's Hardness||550 - 650 HV|
|Young's Modulus||140 - 150 kN·mm-2|
|Bending Strength||0.09 - 0.15 kN·mm-2|
|Compressive Strength||0.65 - 0.80 kN·mm-2|
|total||9 samarium cobalt magnets SM2CO17|
These Samarium Cobalt magnet alloys are an age hardening type with a composition of two atoms of rare earth Samarium Cobalt and 13-17 atoms of transition metals. 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.
Generally, Samarium Cobalt magnets do not need any coatings or platings after processing. Occasionally coating with advanced coatings such as PR1010 is desirable if cleanliness is an issue. The coating in this case acts much like a sealant. Oxidation is not a factor. Occasionally the Samarium Cobalt (SmCo) magnet may have some areas that have areas that discolor and appear as oxidation. This is typically due to some iron impurities and is generally not a cause for plating; the rusting appearance is typically localized in areas and after some discoloration, does not continue through the material.