SmCo Magnet

SmCo magnet is composed of Samarium, Cobalt, and a few transition metals. SmCo magnet is high performance, low temperature coefficient rare earth permanent magnet, and could keep their performance under the maximum working temperature up to 350 degree centigrade.


Manufacturing Process

 

Samarium, Cobalt, and a few transition metals will be made into the SmCo powder, then fine SmCo powder will be compacted in a die and sintered, fusing the powder into a solid material. There are 2 forms of pressing: die pressing and isostatic pressing. Sintered parts normally need some finish machining in order to meet final tolerances.

 

Machining & Tolerance

 

Generally, SmCo magnet must be machined using diamond-grinding techniques. Sometimes, machining operations may be performed on SmCo magnet using carbide tools, but surface finishes thus obtained may be less than optimal.


The Standard tolerances for SmCo magnet are +/- 0.1mm for ground dimensions, but sticter tolerances are possible if specially required.

 

Surface treatments


The corrosion resistance of SmCo magnet is considered good. Although Surface coating or plating is not generally required for SmCo magnet, all kinds of surface coating are also available, like Nickel, Zn, Ni-Cu-Ni, Gold, Silver, Sn,Chrome, ABS coating, Rubber coating, PTFE(Teflon) coating, stainless steel case and Epoxy coating etc.


Magnetizing & Packing


SmCo magnet requires extremely high magnetizing fields, and can be magnetized in any direction as long as it is aligned properly. In some instances multiple pole magnetization is possible with special fixtures. All SmCo magnet is anisotropic, and can only be magnetized in the orientation direction, so particular consideration must be given to this when designing complex assemblies, if it is intended to magnetize after installation.


SmCo magnet is mechanically weak, but magnetically very strong. They should be packed properly in order to help user to handle them safely.

 

Magnetic properties of SmCo magnet

 

Grade Residual Induction Coercive Force Intrinsic Coercive Force Maximum Energy Product Maximum Working Temperature
Br Hcb Hcj (BH)max Tw
mT kA/m kA/m kJ/m3
[kGs] [kOe] [kOe] [MGOe]
SmCo5 YX18 810-920 637-756 1194-1751 135-159 250°
[8.1-9.2] [8.0-9.5] [15-22] [17-20]
YX20 850-950 637-756 1194-1751 151-175
[8.5-9.5] [8.0-9.5] [15-22] [19-22]
YX22 890-1000 661-772 1194-1751 167-191
[8.9-1.0] [8.3-9.7] [15-22] [21-24]
YX24 920-1040 661-796 1194-1751 175-199
[9.2-10.4] [8.3-10.0] [15-22] [22-25]
Sm2Co17 YXS24M 920-1040 318-788 398-1194 175-199 350°
[9.2-10.4] [4.0-9.9] [5-15] [22-25]
YXS24 920-1040 661-796 ≥1194 175-199
[9.2-10.4] [8.3-10.0] [≥15] [22-25]
YXS24H 920-1040 661-804 ≥1990 175-199
[9.2-10.4] [8.3-10.1] [≥25] [22-25]
YXS26M 1000-1060 318-796 398-1194 191-215
[10.0-10.6] [4.0-10.0] [5-15] [24-27]
YXS26 1000-1060 677-820 ≥1194 191-215
[10.0-10.6] [8.5-10.3] [≥15] [24-27]
YXS26H 1000-1060 677-820 ≥1990 191-215
[10.0-10.6] [8.5-10.3] [≥25] [24-27]
YXS28M 1040-1110 318-804 398-1194 207-231
[10.4-11.0] [4.0-10.1] [5-15] [26-29]
YXS28 1040-1110 677-820 ≥1194 207-231
[10.4-11.0] [8.5-10.3] [≥15] [26-29]
YXS28H 1040-1110 677-820 ≥1990 207-231
[10.4-11.0] [8.5-10.3] [≥25] [26-29]
YXS30M 1070-1120 318-804 398-1194 223-247
[10.7-11.2] [4.0-10.1] [5-15] [28-31]
YXS30 1070-1120 700-828 ≥1194 223-247
[10.7-11.2] [8.8-10.4] [≥15] [28-31]
YXS32M 1090-1150 318-804 398-955 231-255
[10.9-11.5] [4.0-10.1] [5-12] [29-32]
YXS32 1090-1150 716-836 ≥955 231-255
[10.9-11.5] [9.0-10.5] [≥12] [29-32]
Low Temp Coeff Sm2Co17 YXL22LT 900-1000 677-756 ≥1194 159-183 350°
[9.0-10.0] [8.5-9.5] [≥15] [20-23]
YXL24LT 920-1020 677-756 ≥1194 175-199
[9.2-10.2] [8.5-9.5] [≥15] [22-25]
YXL26LT 1000-1070 677-812 ≥1433 191-223
[10-10.7] [8.5-10.2] [≥18] [25-28]

 

Physical properties of SmCo magnet

 

Grade Modulus of elasticy Ultimate tensile strength Density Electrical Resistivity Curie temperature Recoil permeability Temp.Coeff.of Br
SmCo5 23 x 106 psi 6 x 103 psi 8.2 g/cm3 5 µ-ohm-cm/cm2 750-770℃ 1.05 From -0.043 to -0.045% / ℃
Sm2Co17 17 x 106 psi 5 x 103 psi 8.4 g/cm3 86 µ-ohm-cm/cm2 825-850℃ 1.05 From -0.03 to -0.032% / ℃