New Permanent Magnets and New Processing Techniques

Since the discovery of Nd2Fe14B in 1984, a number of new phases with uniaxial anisotropy like Sm(Fe,X)12, Sm5(Fe,Ti)17, (Sm,Zr)Fe3, and Sm2Fe17N3 have been investigated. Their intrinsic magnetic properties compare favorably with Nd2Fe14B. Magnetic hardening is possible by rapid quenching or mechanical alloying, which both result in isotropic materials with coercivities of up to 51 kA/cm. Mechanical alloying is a new technique to prepare high- performance permanent magnets at low temperatures. For Nd- Fe- B, isotropic and anisotropic magnets with properties comparable to sintered or melt spun materials can be produced.