Magnets are an exciting thing for all of us. We have seen it one form or the other in our lives. The magnets kept in our Physics laboratories did intrigue us when we had to do experiments. But these magnets are tied to us in more ways than we ever thought of. Everything from motors to the metal detectors of our malls, use some kind of magnet or the other. A commonly used variety of magnets are the rare earth magnets which were developed in the 1980’s. Among them, the Neodymium is the most popular rare earth magnets that are used these days. So, let us know a little more about this magnet.
What are the Neodymium Magnets?
The Neodymium magnet is a form of the permanent magnet that is derived from an alloy made from using rare earth elements. It is the most widely used rare earth magnet because of its affordability and strength of the magnetic field. The alloy contains Neodymium, iron, and boron which form the tetragonal crystal structure of Nd2Fe14B. The magnet was first discovered by General Motors and Sumitomo Special Metals in 1982. Microcrystalline grains form the alloy which allows the magnet to become aligned so that it may have a powerful magnetic field. The magnetic energy value of a Neodymium Magnet is about eighteen times more than the normal magnets in volume.
How are the Neodymium Magnets made?
- The classical powder metallurgy or the sintered magnet process: In this type of production the base materials of the magnet are treated in a furnace and then set into moulds to form ingots. Then they are transformed into a powder which is sintered into dense blocks. Then they are treated with heat and cut into shapes so that they can become magnetized. But a new technique was devised in 2015 where the alloy may take a clay-like structure and then it can be made into different shapes and sizes before magnetization.
- The Rapid solidification or the bonded magnet process: This is another process in which the melt spinning method is utilized on a thin strip of the NdFeB alloy to form the magnet. Then they are made into particles and a polymer is added to it to inject them into bonded moulds. They have low flux intensity but they easily take difficult shape.
The Neodymium magnets come in different grades. The grades depend upon the magnetic flux output that it has on per unit volume. Higher the values, higher the strength of the magnet. It mainly ranges from N35 to N 52. These types of magnets are used in every sphere of life. The most common usages of the Neodymium magnets are in computer hard disks, locks, loudspeakers, electrical motors, cordless tools, voice coils etc.
These days the magnets are also widely used in things like jewelry clasps, children’s toys, and MRI scans. So, it is an important discovery in the field of magnets. The world produces more than 80,000 tonnes of the Neodymium magnet to make our lives easier.