Magnetic materials

Magnetic materials used in our magnet systems

Neodymium-iron-boron (NdFeB)
Alloy made of neodymium, iron, boron with the compound Nd2Fe14B.
NdFeB magnets are hard, but not brittle and oxidise heavily. That is why they are mostly nickel-or zinc-plated. NdFeB magnets indicate a very high energy density so that a very high adhesive forces can be achieved at max. saturation. They can be used in a temperature range of -40°C to + 200°C*. 

Samarium-Cobalt (SmCo)
Alloy consisting of the rare earth metal samarium (Sm) with the metal cobalt (Co). 
Alloy structures
SmCo5 (without iron content)
Sm2Co17 (with 20–25 % iron content) 

These magnets are hard and brittle and can only be machined using diamond tools. They are expensive due to the high cobalt content. SmCo magnets oxidise only slightly and demonstrate good chemical resistance. Due to their high energy density (about 30-40% less than NdFeB magnets), high adhesive forces can be achieved at maximum saturation. They can be used in a temperature range of -40°C to +350°C*.

AlNiCo
Alloys consisting of aluminum, iron, nickel, copper and cobalt. Permanent magnets are made from them using casting methods and technology or sintering.

Due to their magnetic properties, magnets made of AlNiCo have to be very long in the direction of magnetisation in order to have, as open magnets, good demagnetisation resistance. AlNiCo magnets are highly temperature-resistant and can be used in the temperature range -270°C to + 450°C*.

Hard magnetic ferrites (HF)
are made out of iron oxide and strontium carbonate.
Strontium-ferrite compound: SrFe12O19

In contrast to the rare earth magnets, ferrites demonstrate a considerably lower magnetic energy density. These raw materials are available in large quantities and are therefore inexpensive. 

Chipping on the sharp edges are accepted, provided that the original shape of the magnet and its function are maintained. In cases where no chipping is accepted, it must be explicitly specified.

Magnets made of hard ferrites can be isotropic (elements uniform in all directions ->lower adhesive force) or anisotropic (elemental components have a preferred direction -> higher adhesive force). HF magnets can be used in a temperature range of -40°C to + 250°C*. 
The material is hard and brittle and can only be machined using diamond tools. Furthermore, hard ferrites are not sensitive to oxidation and weather conditions; they also show good chemical resistance.

*The maximum service temperature varies however, and depends entirely on the actual alloys, the application, the bonded materials, as well as the geometry of the magnet. Please refer to our product catalogue for precise details on the temperature range of your magnet system. You are also welcome to contact us in person.