As the name suggests, rare earth magnets are made from alloys of rare earth materials. These strong permanent magnets, developed in the 1970’s, are the strongest permanent magnets available, even stronger than ferrite and alnico magnets. However, the name is a bit misleading; the “rare earth” elements theses magnets are made from are not, in fact, very rare. They’re as plentiful as elements like tin or lead.
Types of rare earth magnets
There are two types of rare earth magnets: neodymium and samarium magnets.
Neodymium magnets: these small, metallic magnets are made from neodymium, iron, boron, and other transitional metals and come in disks, rings, and blocks. Neodymium magnets are sensitive to temperature and corrosion, which is why they are generally coated.
Samarium cobalt magnets: these small but strong magnets, made from samarium, cobalt, and iron also come in simple shapes like blocks, disks, and rings. They do not corrode and also do not require any coating.
How are rare earth magnets made?
Through a sophisticated arrangement of atomic particles and their electron spin, rare earth magnets are able to get their incredible strength. Rare earth magnet manufacturing is strictly licensed, though as some of the restrictive patents are expiring, the market has grown, allowing these magnets to be more available.
Mining: The elements and materials come from the ground through mining.
Grinding and mixing: After the materials are mined, they have to be ground up to a powder, then mixed to make the materials that have different magnetic properties.
Pressing: This mixture is next pressed into a form and then an electromagnet optimizes the material for magnetization.
Sintering: Once the particles are in place, they are sintered in place.
Plating/coating: In order to protect the pieces from corrosion or temperature sensitivity, they are coated with platings of nickel, nickel and copper, epoxy, gold, or zinc.
Rare earth magnet applications
What are rare earth magnets used for? Neodymium and samarium magnets can be used for just about anything, commercially and for industrial purposes. There are a variety of useful applications, such as:
Computer disc drives
Industrial equipment protection
Mechanically powered flashlights
Permanent magnet motors in cordless tools
Traveling wave tubes
And many more
Where to buy rare earth magnets
Since rare earth magnets became more accessible and competitive in the 2000’s, you can buy these strong, permanent magnets for commercial or industrial uses. HSMAG Magnetics offers a variety of rare earth magnets at a great value.
For more information on rare earth magnets, visit hsmagnets.com.