What Are Neodymium Magnets?

Production of Neodymium Magnets

Neodymium magnets are produced by two different methods, the classical powder metallurgy or sintered magnet process and the rapid solidification or bonded magnet process. Sintered neodymium magnets are prepared by pulverizing (reducing to fine particles) an ingot precursor (a material, usually metal, that is cast into a shape suitable for further processing), heat treating and finally magnetizing. Bonded neodymium magnets are prepared by a thin ribbon of the neodymium, iron and boron alloy. The ribbon is pulverized into particles, mixed with a polymer and finally magnetized.

Poles of neodymium magnet can be identified very easily. The magnet has two poles, north and south. The simplest identification is by using another neodymium magnet that is already marked. Due to magnetic property, the north pole of the marked magnet will attract the south pole of the unmarked neodymium magnet and repel the north pole. Another way is by using a compass and bringing it close to the neodymium magnet. The south pole of the neodymium magnet will be attracted to the north pole of the compass. Alternately take the neodymium magnet and dangle it by a string so that it rotates freely. The north pole of the neodymium magnet will always point in the geographical north direction.

There are several attributes of neodymium magnets that make them different from other magnets. They are the strongest permanent magnets that exist today and have a very high resistance to demagnetization. Small-size neodymium magnets have a very strong magnetic field and operate well at ambient temperatures. Neodymium magnets are very corrosive and have a low working temperature for heat applications and can catch fire at high temperatures.

In the industry, neodymium magnets have found use in magnetic separators, magnetic filters, alarms and switches and security systems. Neodymium magnets are widely employed in the hard drives of computers. In medicine and health, these magnets are used in magnetic therapy to help alleviate the symptoms and relieve pain caused by health problems like arthritis and in magnetic resonance imaging scanning machines. Neodymium magnets find applications in head actuators for computer hard disks, magnetic resonance imaging, magnetic guitar pickups, loudspeakers and headphones, magnetic bearings and couplings, and electric motors. These magnets are also used in magnetic jewelry clasps and children's magnetic building sets.