REFeB or NdFeB magnets have only been developed recently and consist of the rare earth neodymium, iron and boron. Energy products, which are up to 40% above currently known and used metallic magnets, can be produced using this combination of materials. Permanent magnets made from Neodymium-Iron-Boron alloys enable the realisation of new technological solutions and the reduction of the utilisation of magnetic materials with the same performance level of the system and also provides the possibility of miniaturising the whole system. In contrast to SmCo magnets, the raw materials for NdFeB magnets are more readily available as the content of neodymium in rare earth ores is substantially higher than that of samarium.
Like Samarium-Cobalt magnets, NdFeB magnets are produced by the process of powder metallurgical sintering. The alloys can be produced by different processes: by the melting and blending of certain prematerials or by the reduction / diffusion of rare earth oxides and metals the result of which is then ground. The mono crystalline powder with a grain size of approximately 5 µm is dispensed into the die cavity of a mould. Then pressing under the influence of a magnetic field produces an anisotropic magnet. As an alternative to form pressing, isostatic pressing is also possible in a magnetic field. This aligns the anisotropic powder particles parallel to the direction of the magnetic field. The pressing process condenses the material and fixes the alignment. The magnets are then sintered at temperatures between 1030 – 1100 degrees C in an inert gas atmosphere or a vacuum. Sintering results in shrinkage of between 15 – 20%. The density values measure between 7.4 – 7.6 g/cm³. The components are subsequently heat treated at temperatures of 600 – 900 degrees C. If specific tolerances are required, the components can be ground after heat treatment.
Our Product Range:
Our range comprises a wide selection of Neodymium-Iron-Boron materials with differing magnetic properties. They permit material selection tailored to individual application requirements.
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