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 unmagnetized magnets during transport and assembly often requires a magnetizytion of the fully assembled magnet system.

Possible reasons for the magnetization of magnet assemblies are:

  • Easier handling and packaging
  • Reduction of dirt attrction (e.g. iron dust)
  • Reduced risc 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 Colbald 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 impuls magnetizer.

2. The magnetization process

3. Creation of the outer field