Neodymium-iron-boron magnets

Neodymium-iron-boron magnets, 14 651 Neodymium lasers, 14 698 20 514, 515. 

Even more powerful are the neodymium—iron—boron magnets that appeared in the mid-1980s (35,36). Magnets derived from the Nd Fe B structure exhibit the highest performances obtained industrially eneigy products are >320 kJ/m3 (>40 x 106 GOe) and coercive fields around 950 kA/m3 (12 kOe). These magnets are in the course of a rapid development, eg, in voice coil motors and the automotive industry. There is a promising forecast for several industrial applications. 

Lyman, J. W., Pahner, G. R., 1993b. Recycling of neodymium iron boron magnet scrap. In Report of Investigations 9481 United States Bureau of Mines. 

Another material that has permanent magnetic properties is neodymium—iron—boron, Nd2Fe24B. For an in-depth discussion see reference 7. 

The reduction diffusion process has also been used for the production of powders of the magnetic neodymium-iron-boron alloy (Nd15Fe77B8). The reaction involves use of a powder mix of neodymium oxide, iron, ferroboron and calcium. The reaction is conducted by heating the powder charge mixture at 1200 °C for 4 h under vacuum. Neodymium-iron-boron alloys are much more prone to oxidation than samarium-cobalt alloys and a proprietary leaching procedure is used for the separation of the alloy and calcium oxide. 

New permanent magnet materials, such as samarium-cobalt and, a fortiori, neodymium-iron-boron alloys, are also of special interest in the design of static devices with specific magnetic-field configurations. Apart from high remanence and coercive force values of magnets made of these materials, Chavanne et al. (1987) emphasize the presence of large anisotropy fields in the conception of these devices. 

Lee, R. W., Brewer, E. G. Schaffel, N. A. (1985). Processing of neodymium-iron-boron melt-spun ribbons to fully densed magnets. IEEE Transactions on Magnetics, MAG-21, 1958-63. 

Hammond CR (2015) The elements. In Haynes WM, Bruno TJ, Lide DR(eds) CRC handbook of chemistry and physics, 96th edn, Internet Version. CRC Press, Boca Raton, Section 4, pp 1-36 Herbst JF, Croat JJ (1991) Neodymium-iron-boron permanent magnets. J Magn Magn Mater 100 57-78... 

Capellen, J., K.A. Menzel and K.A. Gschneidner Jr, 1986, Source Book on Neodymium-Iron-Boron Permanent Magnets, IS-RIC-9 (Rare-earth Information Center, Iowa State University, Ames, lA). 

Samarium is a rare and relatively expensive material furthermore, the price of cobalt is variable, and its sources are unreliable. Consequently, the neodymium-iron-boron, Nd2Fci4B, alloys have become the materials of choice for a large number and wide diversity of applications requiring hard magnetic materials. Coercivities and energy products of these materials rival those of the samarium-cobalt alloys (Table 20.6). 

Z.S. Wronski, Rapid solidification of iron-neodymium-boron magnetic alloys, in rapid solidification technology-an engineering guide, In T.S. Srivatsan, Editor. (1993), Technomic Publishing, Lancaster, Basel, pp. 257-298. 

In recent years, new permanent magnets have come on the market. They are made of an alloy of iron, neodymium and boron. They exhibit strong stable fields. They are strong enough that they have displaced superconductor magnets in some classes of medical magnetic resonance machines. Their use... 

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