The problem of demagnetization will be encountered in the actual use of motor magnet. Today, the motor magnet manufacturer AISEN MAGNETS introduces the main reasons of permanent magnet demagnetization in actual motor use.
1. Demagnetization caused by motor magnet material itself
The servo motor we are using now is NdFeB permanent magnet, which has the advantages of high remanence and high intrinsic coercivity. At present, it is a high magnetic material. Rare earth content is high, iron and boron are cheap, and there is no strategic material cobalt. However, the disadvantage of NdFeB magnet material is its poor thermal stability. The n38sh NdFeB permanent magnet we used has a heat resistance of 150 ° C. As long as the temperature exceeds 150 ° C, it will cause irreversible demagnetization. In addition, NdFeB magnets contain a large number of iron and neodymium metal materials, and the surface is easy to be oxidized. Usually, there is an epoxy coating or an electrophoretic or electroplated coating. If the coating process is not qualified, the permanent magnet will be locally oxidized in the process of use. This leads to demagnetization.
2. Demagnetization caused by motor design
If the motor is not fully understood in the design of the motor, so that the actual working point is below the inflection point of the demagnetization curve, irreversible demagnetization of the motor magnet will occur in the use process. In addition, the working point calculated during design is usually the average working point of permanent magnet. However, due to the local difference of permanent magnet materials, the maximum demagnetization point of permanent magnet must be calculated. In addition, when designing the motor, please fully consider whether the internal temperature rise of the motor is within 105K. Beyond this range, irreversible demagnetization will also occur.
3. Improper use of motor magnet leads to demagnetization
The environment in which the motor is used is very bad, especially in the case of high temperature or severe mechanical vibration, which may make the motor magnet demagnetized. In addition, when the motor is overloaded for a long time, the motor may be irreversibly demagnetized due to high temperature.
AISEN MAGNETS focused on development and manufacturing of Neodymium magnet, has more than 10 years manufacturing experience in producing various sizes, different shape and surface coating. Over 45 different grades of neodymium magnet (strong magnet) widely used in many industry.
Our Production line including vacuum melting, Jet mill, Isostatic press, vacuum sintering, machining and magnetization. Our annual design output is 1000tons, currently output is 800tons. Our experienced engineers work closely with customer to find out the best possible solutions to meet your requirements.
