Permanent magnets

A magnet is a body that generates a magnetic field. A distinction is made between permanent magnets, which provide a constant magnetic field, and electromagnets, which only generate a field when they are exposed to an electric current.
There are a number of different permanent magnet materials, of which neodymium and samarium cobalt are the two with the highest magnetic performance. Ferrite magnets and AlNiCo are two other types that are widely used nowadays, especially ferrite magnets.
All these types of magnet can also be supplied in a plastic bonded design in which the magnetic force is lower but other key properties such as tighter tolerances and better adaptation are included. In short, there is a type of magnet for every application.

Magnets are suitable for applications in which you require a constant magnetic flux without supplying energy from outside. In applications such as generators and motors this is a great advantage. Sensors in vehicles are another major area of application where the magnet emits a magnetic flux regardless of dirt and other interference in a harsh environment.
Compotech mostly works with neodymium, ferrite and samarium cobalt magnets nowadays but can also develop solutions with AlNiCo and plastic bonded magnets.
We prefer to get involved early in the development phase since it is important to use the right magnetic material for the right area of application.

Neodymium magnets

Neodymium magnets are characterised by a high field strength but lower temperature and corrosion resistance, which means that it may be necessary to surface treat the magnet to prevent corrosion. This is where we can help you to find the right grade for the right application with the right surface treatment. The neodymium magnet is the class of magnet whose use is increasing fastest today.

Neodymium magnets do not consist of pure neodymium but are a sintered powder mixture of neodymium, iron and boron (NdFeB).

Samarium cobalt magnets

A type of magnet that is characterised by a high field strength and temperature resistance combined with relatively good corrosion resistance. These characteristics mean that samarium cobalt magnets are suitable for use in motors, for example.

Ferrite magnets

Cost-effective magnets with a low field strength, but very good corrosion properties and relatively good temperature resistance. This material can be used when you have the space and want a cost-effective solution.

Plastic bonded magnets

Plastic bonded magnets can be supplied in both a compression moulded and injection moulded design. All available materials, neodymium, samarium cobalt and ferrite, can be supplied as plastic magnets, but with a slightly lower magnetic performance. The advantage is that you can obtain better tolerances and more flexible magnetisation.

Permanent magnet systems

In almost all cases a magnet will be combined with iron to increase the performance. We call this a magnetic system and we can supply both magnet rotors, magnetic couplings and magnetic holding systems with the associated magnetic calculation consultation.