Magnetic Materials

ferrite magnets
Alnico Magnets
Neodymium Magnets
Bonded magnets

F Squared Magnetics Ltd Can supply a complete range of magnetic materials from the more cheaply produced Ferrite (ceramic ) magnets up to the most exotic Rare Earth materials.

Ferrite (ceramic) magnets.

These magnets are generally produced by pressing powder or slurry into a mould, firing in a kiln, and grinding the pressed depth to tight tolerances. To achieve the maximum performance for this material it has to be pressed in a magnetic field, this determines the final direction of magnetisation. This is known as anisotropic.

Tooling charges for special shapes or sizes are very high and it is advisable, where possible, to use a standard, already tooled, shape, unless quantities are very high, 100, 000 or more.

The most common magnets are of rectangular or square shaped and can be produced by cutting or slicing from large standard blocks.
Typical Bhmax range 6.4 to 33 kJ/m³ (0.8 to 4.2 MGOe)

Alnico magnets.

 

These magnets, made by casting or sintering, are made from Aluminium, Nickel, Cobalt and Iron. Whilst they have, by now, mostly been superceded by rare earth magnets, they are particularly in demand for their consistent magnetic performance over a large temperature range (-40°C to 525°C) and corrosion resistance.

Typical Bhmax range 9.0 to 72 kJ/m³ (1.13 to 9.0 MGOe)

Rare earth magnets

Neodymium magnets.

Introduced in 1983, Neodymium Iron Boron, is now the most common and cheapest of these particularly high-energy materials. They are produced by pressing powder in a very high magnetic field and sintering. Due to the nature of the material it is necessary, except in special circumstances, for the magnet to be supplied with a coating that prevents corrosion. Whilst they do appear expensive, their ability to allow miniaturisation of the user product means that in terms of energy for unit volume the materials are quite cheap

Typical Bhmax range 207 to 326 kJ/m³ (26 to 41 MGOe)

Samarium Cobalt magnets.

Was developed prior to Neodymium in 1977. Produced using a similar manufacturing technique to Neodymium, it's advantages are it's higher temperature range up to 350°C. However it's fragile nature limits it's applications.

Typical Bhmax range 160 to 225 kJ/m³ (20 to 28 MGOe) 

Bonded Ferrite and Neodymium magnets.

Both Ferrite and Neodymium magnets can be produced in plastic bonded forms, all be it at much lower magnetic performances, (eg. Fridge Door gaskets and magnets). F Squared Magnetics Ltd will be happy to advise customers of the best material for their application.

Typical Bhmax range 4 to 100 kJ/m³ (0.5 to 12.5 MGOe)

For details on handling and care of magnetic materials, please request a data sheet.

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