Neodymium magnet, also known as NdFeB magnet, is a tetragonal crystal system composed of neodymium, iron, and boron (Nd2Fe14B). In 1982, Sumitomo Special Metal's Sanjin Sagawa discovered neodymium magnets. The magnetic energy product (BHmax) of this magnet is greater than that of samarium cobalt magnets, and it was the material with the magnetic energy product of the world at that time. Later, Sumitomo Special Metals successfully developed the powder metallurgy process, and General Motors successfully developed the melt spraying process, which can prepare neodymium iron boron magnets. This type of magnet is currently the second most magnetic permanent magnet after zero degree holmium magnets, and is also a commonly used rare earth magnet. Neodymium iron boron magnets are widely used in electronic products, such as hard drives, mobile phones, headphones, and battery powered tools.