Rare earth element-Fe-B or rare earth element-Fe-Co-B permanent magnet powder excellent in magnetic anisotropy and corrosion resistivity and bonded magnet manufactured therefrom

摘要

A R-Fe-B or R-Fe-Co-B permanent magnet powder excellent in magnetic anisotropy and corrosion resistivity, having powder particles. The powder particles each consist essentially of, in atomic percentage:P PR: 10-20%PPB: 3-20%; PPat least one element selected from the group consisting of Ti, V, Nb, Ta, Al, and Si: 0.001-5.0%; andPPFe and inevitable impurities: the balance,PPThe R-Fe-Co-B magnet powder further contains 0. 1-50% Co.PPThe powder particles each have an aggregated recrystallized structure having a main phase thereof formed by a R.sub.2 Fe.sub.14 B or R.sub.2 (Co,Fe).sub.14 B type intermetallic compound phase having a tetragonal structure. The intermetallic compound phase is formed of recrystallized grains aggregated therein and includes at least 50 volumetric % of recrystallized grains having a ratio b/a smaller than 2 provided that a is designated by the smallest diameter of each of the recrystallized grains, and b is by the largest diameter thereof. The recrystallized grains form the aggregated recrystallized structure having an average grain size within a range of 0.05-20 &mgr;m.