Permanent Magnet for Motor
Permanent magnet for motor is one of important and high-end applications. In order to achieve optimal performance of PM motor, motor designers need to continually change their design and find best material for motor. Several factors will affect the choice of motor magnet.

1. Magnetic Material: 
    Sintered NdFeB magnet has high magnetic performance (including high magnetic flux, remanence, coercive force, resistance to magnetic demagnetization, and low temperature coefficient, loss of irreversible). It can improve motor performance and reduce the volume as well. It is main magnet material for PM motor.
    Bonded NdFeB magnet is well known for good plasticity. It suits for complex shape magnet or magnet with multipole magnetization direction. Usually, mould is needed for its production.
    Ferrite is an old magnet material which used on PM motor. It’s heavy weight but cheap price.
    SmCo can work under high working temperature. The magnetic force is weaker than Sintered NdFeB magnet, but also very powerful.
    AlNiCo with very high working temperature 450-550℃ is the oldest magnet material for motor and replace by ferrite later.
2. Magnet Max. Working Temperature: Sintered NdFeB magnet 150℃ (N35SH, N38SH, N42SH, N45SH), 180℃ (N35UH, N38UH, N40UH) , 200℃ (N35EH, N38EH); Sm2Co17 300℃
3. Magnet Shape: segment (arc), wedge, bread, block, ring, or special shape

4. Magnet Working Environment: low weight loss (high corrosion resistance)
5. Magnet Coating: NiCuNi, Zn, Black epoxy, Grey epoxy etc. To make full use of magnet performance and control tolerance well, sometimes the plating of magnet uses phosphorization or passivated for temporary protection
6. Magnetized direction: it depends on magnet design. In order to get best performance, magnetic declination can’t be ignored.
7. Magnet tolerance: a lot of motor magnets are made of segment magnets, and small tolerance is very important to reduce air gap and assemble a ring. 

China Magnets Source Material Limited is rich in experience of motor magnet manufacture, such as magnet for flat brushless motor, DC Motor, AC motor, stepper motor , servo motor, synchronous motor; magnet for mini motor or special motor; magnet for high temperature to high humidity; magnet for regular shape or irregular shape.You are welcome to contact us for more information. Our engineers also are ready to provide technical assistance.