Ndfeb disc magnets are the most widely used rare earth magnet. The nineteen-eighties brainchild of General Motors and Sumitomo Special Metals, they are the strongest rare earth magnet ever made. Developed primarily for use in engines, they have become the lynch pin of many modern day conveniences.
Rare earth ndfeb magnet are the strongest permanent magnets available. Though their name implies they are difficult to find, the opposite is actually true. The alloys used to make these magnets are about as common as tin. Ndfeb, or neodymium, is the strongest form of rare earth magnet. It was created in the eighties by GM and their magnet supplier as an alternative to samarium cobalt, which was becoming too expensive. As it became more widely used, the price came down so much that new applications were found for the compound.
There are two main advantages to ndfeb disc magnets. The first is the price. Neodymium is a cheaper compound to create, therefore it is cheaper to buy. This opens up a whole new bunch of uses for the magnet that may not have ever been considered otherwise. The second is strength. Stronger than its counterparts, neodymium magnets produce fields far surpassing those of its brethren.
Along with the advantages are the inevitable disadvantages. Ndfeb magnets are so strong that they pose a very real risk to those who work with them. They are strong enough to break a bone should one be caught between two magnets or a magnet and an attractive metal. For children playing with magnetic toys, this can cause a whole different sort of complication. Swallowing a magnet can cause major damage to the G.I. tract. Corrosion is also an enemy for neodymium, as it is very susceptible. Also very brittle, these magnets easily fracture when struck with any kind of force, which can cause flying projectiles. In most applications, the magnets are coated with something like nickel in order to avoid breakage and corrosion.
After GM patented the neodymium magnet, a whole new world of opportunities and inventors opened up. Strong magnets have gone from almost exclusively industrial applications to being found everywhere. Some of the most common places to find rare earth magnets today are computer hard disks, MRI technology, cordless tools, compressor engines, magnetic guitar pickups, loudspeakers, and headphones. They are also widely found in magnetic jewelry clasps, modern sport parachute equipment and children's magnetic toys. Surprisingly, they are also key components in hybrid and electric drive engines.
Ndfeb disc magnets can be easily found in any number of applications. Due to their superior strength, price and production capabilities, they have gone from obscurity to magnetic fame in about thirty years. As needs change and computers continue to spread out and encompass all regions of life, these magnets may become more and more important to society.