Rare Earth Magnets

Rare earth magnets consist mainly of intermetallic compounds of rare earth metals (samarium, neodymium) and transition metals (such as cobalt, iron). In contrast to hard ferrite magnets, milling, pressing, and sintering is carried out in an inert gas atmosphere. The magnets are pressed either in an oil bath (isostatically) or in a die (axially or diametrically). Afterward, they may be further processed, for example by grinding with diamond discs.

History
Development SmCo: Middle of the 1960s
Use: End of the 1960s/beginning of the 1970s

Development NdFeB: Beginning of the 1980s
Use: Middle of the 1980s

Production begins at MS-Schramberg
1986

Raw material availability
The essential constituents of SmCo are samarium and cobalt; those of NdFeB are neodymium and iron. Samarium and neodymium occur abundantly as ores. They are classified as rare earth metals in the periodic table of elements. Cobalt also occurs in sufficient abundance as a natural raw material.

Raw material sources
Neodymium, samarium and cobalt are mined in various countries around the globe.

Type of material
Metallic

Manufacturing process
Pressing and sintering in inert gas

Application areas and particular properties
Rare earth magnets exhibit very high energy density. They are indicated wherever maximum force and magnetic flux density are required in small spaces. Their high energy density makes it possible to use miniature magnets, for example in sensor technology, and more compact modules, for example in motor engineering.