RARE-EARTH SINTERED MAGNET

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PROBLEM TO BE SOLVED : To provide a rare-earth sintered magnet having improved corrosion resistance. SOLUTION : The rare-earth sintered magnet according to the invention is a rare-earth permanent magnet having a R-T-B based composition, where R is at least one element selected from the group consisting of Y and rare earth elements, T is at least one metal element including Fe and/or Co, B is B and/or C. On condition that an R-rich phase (R is a rare earth element) is present, provided that the R-rich phase meets the condition, (Fe+Co)/(LR+HR+Fe+Co)≤0.2 by atomic ratio (where LR represents Y and light rare earth elements of 57 La to 63 Eu, and HR represents heavy rare earth elements consisting of 64Gd to 71 Lu) at a grain boundary triple point, the R-rich phase has therein a region which satisfies the condition : HR/(LR+HR)≥0.01 (by atomic ratio), and the region meeting HR/(LR+HR)≥0.01 accounts for 10 to 90% by areal ratio at the grain boundary triple point. COPYRIGHT : (C)2013, JPO&INPIT