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Abstract

Disclosed is a method of preparing a micro-structured powder for bonded magnets having high coercivity, which is advantageous in terms of low preparation costs by recycling magnet scraps, simplified mass production, minimal environmental contamination by such a recycling process, and the preparation of stable anisotropic powders having high coercivity. Further, a magnet powder prepared by the above method is provided. The current method is characterized in that R--Fe--B type anisotropic sintered magnets or scraps thereof are crushed to prepare 50 500 .mu.m sized magnet powders, which are then mixed with 1 10 wt % of rare earth fluoride (RF.sub.3) powders and thermally treated at high temperatures (500 1100.degree. C.) in a vacuum or an inert gas, to cause the change of matrix-near surface and grain boundary of the powders. Thus obtained powders include a matrix phase having R.sub.2Fe.sub.14B crystal structure, a R-rich grain boundary phase containing rare earth fluoride, and other phases, in which the matrix phase has an average grain size of 1 20 .mu.m, and the powders have an average size of 50 500 .mu.m with superior magnetic characteristics of (BH)max.gtoreq.20 MGOe and iHc.gtoreq.5 kOe.

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