The production of NdFeB magnets begins with melting of the alloy and the careful
addition of special elements to enhance the particular properties required of
the finished magnet.
The ingot is then crushed and milled to a fine powder under protective
atmosphere. Depending on the type of magnet being produced, the powder is either
isostatically pressed into a block or die pressed to a particular component
shape. During the compaction it is important to apply a large alignment field to
orientate the particles for the preferred magnetic direction.
The compacts are transferred to furnaces which operate under high vacuum. The
sintering process is completed by a separate heat treatment stage to develop the
magnetic properties.
Finishing of the magnets is accomplished by grinding to the required tolerance
or slicing a large block into the desired shape.
All sintered rare earth magnets are characterized by being
hard and potentially brittle compared to steels. Magnets based upon samarium
cobalt are more stable in harsh environments but are much less economical than
neodymium iron boron materials. For high temperatures there are grades of NdFeB
to survive up to 392°F (200°C). A range of protective coatings is available.
Components may be magnetized before final inspection, packing and despatch.
EAM’s knowledgeable product development team will assist you
in choosing the optimal combination of binder and magnet
material for your specific application.
