Magnetically anisotropic rare earth-based nanocomposite permanent magnet

摘要

Disclosed is a novel magnetically anisotropic rare earth-based permanent magnet having a nanocomposite structure consisting of a hard magnetic phase such as Nd₂Fe₁₄B and a soft magnetic phase such as bcc-iron, Fe₃B and Fe₂B in a volume ratio of 10:90 to 90:10 uniformly dispersed each in the other in a fineness of a few tens nanometers, in which particles of the hard magnetic phase are aligned in a direction relative to the easy magnetization axes of the particles. Such an anisotropic permanent magnet can be prepared by the method comprising: preparing a starting amorphous alloy of a composition susceptible to dispersion precipitation of the hard magnetic phase, for example, by the melt-spun method; forming the amorphous alloy into a magnet block; heating the magnet block at 600 to 1000° C. to effect dispersion precipitation of the hard magnetic phase; and deforming the magnet block at the elevated temperature by compression unidirectionally so that the particles of the hard magnetic phase are aligned relative to the easy magnetization axes of the particles.