Rare-earth magnet and manufacturing method thereof and magnet motor

摘要

The object of the present invention is to provide a rare earth magnet which enables to achieve a good balance between high coercive force and high residual magnetic flux density, and its manufacturing method. The present invention provides a rare earth magnet in which a layered grain boundary phase is formed on a surface or a potion of a grain boundary of Nd₂Fe₁₄B which is a main phase of an R-Fe-B (R is a rare-earth element) based magnet, and wherein the grain boundary phase contains a fluoride compound, and wherein a thickness of the fluoride compound is 10 mum or less, or a thickness of the fluoride compound is from 0.1 mum to 10 mum, and wherein the coverage of the fluoride compound over a main phase particle is 50% or more on average. Moreover, after layering fluoride compound powder, which is formed in plate-like shape, in the grain boundary phase, the rare earth magnet is manufactured by quenching the layered compound after melting it at a vacuum atmosphere at a predetermined temperature, or by heating and pressing the main phase and the fluoride compound to make the fluoride compound into a layered fluoride compound along the grain boundary phase.