SmCo magnet
SmCo magnet
SmCo magnet is a high performance low temperature coefficient permanent magnet made of samarium and cobalt and other rare earth elements. The main advantage of SmCo magnets: high magnetic capability, excellent temperature stability, superior corroding-resistance and oxideizing-resistance. SmCo magnet is widely used in motors, watch, transducers, instruments, positional detector, generators and radar etc.
The characteristic and application of SmCo magnets:
1. SmCo permanent magnet has high magnetic energy product and high coercive force. Its properties are better than AlNiCo, ferrite permanent magnet. Its maximum magnetic energy product is up to 239KJ/m3 (30MGOe), which is three times than AlNiCo8 permanent magnet, eight times than ferrite permanent magnet (Y40). So the permanent magnetic component made from SmCo permanent magnets is small, light and stable in property. It is widely used in electronic acoustic and telecommunication appliance, electronic motor, measure meter, peg-top, electronic watch, microwave appliance, magnetic machine, sensor and other static or dynamic magnetic routes.
2. The curie temperature of the SmCo permanent magnet is high and its temperature coefficient is little. So it is suitable for using at 300℃ high temperature.
3. SmCo permanent magnet is hard and bristle. Its rigidity strength, tensile and press strength are low. So it is not suitable for framework.
4. The main ingredient of SmCo permanent magnet is metal Cobalt (Co≥99.95%). So its price is high.
5. SmCo permanent magnet needn't to be coated because it is difficult to be eroded and oxidized.
Physical & Mechanical Properties of Sintered SmCo
Material | Sm2Co17 | SmCo5 |
Physical Properties | ||
Curie temperature | 800~850℃ | 700~750℃ |
Thermal expansion coefficient (//) | 8×10-6/℃ | 6×10-6/℃ |
Thermal expansion coefficient (⊥) | 11×10-6/℃ | 13×10-6/℃ |
Thermal coefficient | 10Kcal/mhr℃ | 11Kcal/mhr℃ |
Specific heat | 8×10-2Cal/g℃ | 9×10-2Cal/g℃ |
Resistivity | 8.6×10-5Ω-cm | 5.3×10-5Ω-cm |
Mechanical Properties | ||
Bending strength | 15Kg/mm2 | 18Kg/mm2 |
Compressive strength | 82Kg/mm2 | 102Kg/mm2 |
Tensile strength | 3.6Kg/mm2 | 4.1Kg/mm2 |
Young's modulus | 1.2×104Kg/mm2 | 1.6×104Kg/mm2 |
Vickers Hardness | 500~600Hv | 450~500Hv |
Typical magnetic properties of SmCo magnets
系列 | 牌号 | 剩磁Br ( 20°C) | 矫顽力(Hcb) | 内禀矫顽力(Hcj) | 最大磁能积 | 密度 | 最大工作温度 | ||||
T | KGs | KA/m | KOe | KA/m | KOe | KJ/m3 | MGOe | g/cm3 | °C | ||
钐钴1:5 | XG18 | 0.84-0.89 | 8.4-8.9 | ≥661 | ≥8.3 | ≥1751 | ≥22.0 | 135-151 | 17-19 | 8.1-8.3 | 250 |
XG20 | 0.89-0.93 | 8.9-9.3 | ≥685 | ≥8.6 | ≥1751 | ≥22.0 | 151-167 | 19-21 | 8.1-8.3 | 250 | |
XG22 | 0.92-0.96 | 9.2-9.6 | ≥708 | ≥8.9 | ≥1751 | ≥22.0 | 167-183 | 21-23 | 8.1-8.3 | 250 | |
XG24 | 0.96-1.00 | 9.6-10.0 | ≥740 | ≥9.3 | ≥1751 | ≥22.0 | 183-199 | 23-25 | 8.1-8.3 | 250 | |
钐钴2:17 | XGS26 | 1.02-1.05 | 10.2-10.5 | ≥748 | ≥9.4 | ≥1433 | ≥18.0 | 191-207 | 24-26 | 8.2-8.4 | 300 |
XGS28 | 1.03-1.08 | 10.3-10.8 | ≥756 | ≥9.5 | ≥1433 | ≥18.0 | 207-223 | 26-28 | 8.2-8.4 | 300 | |
XGS30 | 1.08-1.10 | 10.8-11.0 | ≥788 | ≥9.9 | ≥1433 | ≥18.0 | 223-239 | 28-320 | 8.2-8.4 | 300 | |
XGS32 | 1.10-1.13 | 11.0-11.3 | ≥812 | ≥10.2 | ≥1433 | ≥18.0 | 231-255 | 29-32 | 8.2-8.4 | 300 | |
XGS33 | 1.12-1.16 | 11.2-11.6 | ≥845 | ≥10.6 | ≥1433 | ≥18.0 | 239-263 | 30-33 | 8.2-8.4 | 300 | |
XGS26H | 1.02-1.05 | 10.2-10.5 | ≥748 | ≥9.4 | ≥1990 | ≥25.0 | 191-207 | 24-26 | 8.3-8.5 | 350 | |
XGS28H | 1.03-1.08 | 10.3-10.8 | ≥756 | ≥9.5 | ≥1990 | ≥25.0 | 207-223 | 26-28 | 8.3-8.5 | 350 | |
XGS30H | 1.08-1.10 | 10.8-11.0 | ≥788 | ≥9.9 | ≥1990 | ≥25.0 | 223-239 | 28-30 | 8.3-8.5 | 350 | |
XGS32H | 1.10-1.13 | 11.0-11.3 | ≥812 | ≥10.2 | ≥1990 | ≥25.0 | 231-255 | 29-32 | 8.3-8.5 | 350 | |
XGS-33H | 1.12-1.16 | 11.2-11.6 | ≥845 | ≥10.6 | ≥1990 | ≥25.0 | 239-263 | 30-33 | 8.3-8.5 | 350 | |
Remark:
What we list herein are only typical grades of SmCo magnets. We also could manufacture various magnetic properties according to the customer’s requirements.
Reference points for SmCo magnets:
SmCo magnets are highly prone to chipping and cracking, and specialized machining techniques are required. Press-fit assembly is not recommended because of their brittle nature. The SmCo materials are sensitive to thermal shock and hairline fractures can occur if subjected to thermal shock. Where cosmetic appearance of a magnet is important, this should be specified to us prior to ordering.
SmCo magnets are anisotropic, and can only be magnetized in the orientation direction. In general, magnetizing fields of about 35 to 45 kOe are required to saturate SmCo materials. This is not common to produce and large power supplies in conjunction with carefully designed magnetizing fixtures must be used. A special consideration must be given to this when designing complex assemblies if it is intended to magnetize after assembly.
Two types of SmCo magnets are SmCo5 and Sm2Co17. The 2-17 composition is also more corrosion resistant and more stable at very high temperature.