Rare Earth Permanent Magnets — the Contribution of CEAM

Abstract

The impact of the discovery in 1983 of a high-performance iron-rich rare-earth permanent magnet has been rapid and far-reaching. This new material is probably the most significant advance in permanent magnetism since the development of ferrites in the 1950s. It is progressively supplanting samarium-cobalt (1:5 and 2:17) in many applications, and may eventually replace alnicos. Exciting new products and engineering prospects are opened up by the availability of magnets with an energy product in excess of 250 kJ.m^-3 and a service temperature of up to 150°C. In CEAM, research has been conducted in parallel with a view to understanding and improving the magnetic properties of Nd₂Fe₁₄B, and related phases, searching for new iron-rich phases that may prove to be equally interesting, improving the processing and corrosion resistance of Nd-Fe-B magnets and using the magnets in prototype devices. This section is designed to highlight the contribution of CEAM and guide the reader to what is of interest to them in the rest of the book.