Magnetization of permanent magnets
1. Delivery of permanent magnets:
Handling magnetized magnets may cause major problems for transport
and assembly. They might cause injury due to dangerous forces, attract
dirt or may hard to be kept in their assembly location.
Thus the easy handling of un-magnetized magnets during transport and
assembly often requires a magnetization of the fully assembled magnet
system.
Possible reasons for the magnetization of magnet
assemblies are:
- Easier handling and packaging
- Reduction of dirt attraction (e.g. iron dust)
- Reduced risk of injury
- In some magnet system the magnetic layout requires iron return
paths for the stability of the magnets. This may be of high relevancy
for AlNiCo or Cobalt alloys.
- Better profitability in case of high quantities
Most of the permanent magnets are not magnetized directly after production.
Sinter magnets for example are demagnetized completely due to the high
sinter temperature. They have to be magnetized afterwards by application
of a high external field.
Some plastic bonded magnets may be magnetized directly in the injection
mold. However it often still is helpful to strengthen some weakly magnetized
portions by application of a higher external field of an impulse magnetizer.
2. The magnetization
process

3. Creation of
the outer field
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