8 Factors to Affect the Magnetic Force of Permanent Magnet

China-Magnets-Source-Material.com | Best Magnetic Solution

The magnetic force for permanent magnet can stay for a long time but it is not really permanent. There are 8 factors which will affect magnetic force.
1. The material formulation
Material formulation limits magnetic properties fundamentally. Sintered ndfeb magnet is the strongest and alnico is the weakest. There is also difference for the same material based on formulation. The magnetic force for grade N45 is higher than grade N35 for the same size magnet.
2. Magnet size and shape
3. The magnetization saturability
Only when full charged, magnetic force can be achieved completely.
4. Design of magnetic circuit
Different magnetized direction, the magnetic force is different. For a cylinder magnet, magnetic force by axial-magnetized is stronger than diameter-magnetized.
5. Working temperature
Magnet is very sensitive to working temperature, especially for sintered ndfeb magnet. The momentary and continuous highest temperature of environment may cause certain demagnetization including recoverable and unrecoverable, reversible and irreversible. According to working temperature range 80-200 celsius, sintered ndfeb magnet is divided into several grade series (N, M, H, SH, UH, AH etc.). The cost will be expensive for high working temperature grade. So you need to consider your working temperature and choose the right grade. The loss of magnetic force can be ignored under working temperature permitted range. But magnetic force will decrease rapidly while working under a limit working temperature for a long time.
6. Working humidity
Sintered ndfeb magnet is easy to be oxidized and then loss its magnetic force. We use coating to avoid this problem. But this is not a permanent solution. So the dryer, the better.
7. External magnetic field
Magnetic force will reduce while placing opposite poles around magnet, only when the magnetic field of opposite poles is several times larger than magnet itself, the reduction will be evident.
8. Strong shock
It will reduce magnetic force, but needs long time.

The Use of NdFeB Magnet by china-magnets-source-material.com

Here, let’s introduce the use of NdFeB magnet in the market.

As the third generation permanent magnet material, NdFeB magnet has rather high properties. The NdFeB magnets apply to the industries for energy sources, transportation, machinery, medical treatment, IT, and home appliance. Especially with the development of information technology, it brings so many new uses for the NdFeB magnets.

In the electro-acoustic industry, the loudspeaker, receiver, microphone, annunciator all are using NdFeB.

In the electrical machine industry, they also can’t work without NdFeB magnet, such as VCM, CDDVD-ROM, dynamo, electromotor, micro machine, ac motor and so on.

In conclusion, it is a new sight to use more and more NdFeB products in our modern daily life.