Neodymium rare earth magnets are the most powerful magnet known to man. These magnets are called ?permanent? magnets because they are made from materials that create their own magnetic field, such as common household refrigerator magnets do. They simply magnetize themselves. Rare earth magnets are called such because to make them, one must combine certain rare elements together, such as the 15 different lanthanides, scandium, and yttrium. The magnetic fields of these rare earth magnets are strong enough to use as a hard driver eraser and it can even de-magnetize other magnetic media as well as disrupt the normal process of CT scanners if the magnet is large enough. Additionally, these magnets can also erase any cards using magnetic stripes to contain personal information, such as identification cards or credit cards.
Neodymium magnets were first created in the early 1982 and are the second type of rare earth magnet in creation. The compound used to make this magnet was discovered by Sumitomo Special Metals and General Motors Corporation because the other type of rare earth metal magnet, Samarium-cobalt or SmCo magnets, were too expensive to use efficiently in production lines. Two types of the rare earth magnets exist; sintered and bonded. The sintered neodymium rare earth magnets are very corrosive and for that reason, manufacturers commercial products using the magnet use a protective coating such as nickel or copper and nickel plating. These materials can stop the magnet from corroding while in use.
Manufacturers of sintered magnets prepare them by taking the magnetic powder and pulverizing it with liquid-phase sintering and ingot precursor. Then, it is formed into blocks of which are cut into specific shapes while heated and then given its magnetic qualities. Bonded magnets use two types of alloys; the Nd-Fe-B and Nd2Fe14B alloys of which are prepared using the melt-spinning process. This process takes the two alloys and crushing them into small particles, almost microscopic in nature, then mixing them with polymers. Afterwards, it is set into bonded magnets.
In either form, neodymium rare earth magnets can be dangerous to use if a person is not careful using them. This is especially true of children who may not have the strength to hold them tightly. The sheer force and strength of the magnets can cause serious injuries should a finger accidentally become stuck in between two of the magnets. One single neodymium magnet of only a centimeter in size has enough force to cause these injuries. Additionally, if two of these magnets are close together, they can cause such as magnetic field that they will force together with such astounding strength that they may break. The resulting magnet chips have been known to cause injury because they are sent flying at such a strong force.
