The Phylogeny of NdFeB Magnets

　　The Intermetallic compounds consisting of metal from the rare earth elements R, iron, boron. R is neodymium or a combination of neodymium with other rare earth elements such as cobalt, aluminum, vanadium, also sometimes used to replace part of the iron. NdFeB magnets with strong magnetic anisotropy and a high saturation magnetization, and the magnet components of its representative is Nd15Fe77B8 (atomic ratio).

　　Permanent magnetic materials, the highest performance of sintered Nd-Fe-B magnets, commercial products, the maximum energy product (BH) max = 360kJ/m3 intrinsic coercivity iHc reach 800 ~ 1400kA / m. However, the magnet of the Curie temperature is low (314 ° C), temperature stability and poor corrosion resistance, limits the use at higher temperatures, but in most cases requires the use of a protective coating. The manufacturing process of the Nd-Fe-B magnet powder have metallurgy and melt-spinning method. Because of excellent magnetic properties, the Nd-Fe-B type magnet to obtain a wide range of applications, and mainly used for electric motors, generators, acoustic transducers, various sensors, medical devices and magnetic machine.

　　NdFeB magnets is a new type of permanent magnets by contemporary Japanese scientists left Sichuan real invention, it is composed of three elements from neodymium, iron and boron alloy magnets, the is magnetic strongest permanent magnets, neodymium atoms is flat the electron cloud is limited, so that the iron atom does not shift, thereby forming a magnetic force constant.

　　The 29th the metal Symposium on November 1983, Japan's Sumitomo Special Metals Corporation first proposed neodymium iron boron permanent magnetic materials manufacturing, is really "a ripple" Since then, caused the new magnetic properties of Nd-Fe-B boom of metal Research, more than a decade, the increasing patent, to maintain the "King" of the new magnetic metal patent status the Japan Sumitomo special Metals Corporation in this regard also.