R−t−b系希土類永久磁石

Abstract

【課題】低い着磁磁界でより高い着磁率を得るとともに、着磁特性曲線がより低高磁界側に存在するR−T−B系希土類永久磁石を提供する。 【解決手段】R 2 T 14 B相(ただし、RはYを含む希土類元素の1種又は2種以上、TはFe又はFe及びCoを必須とする1種又は2種以上の遷移金属元素)からなる主相と、主相よりRを多く含む粒界相とを備えた焼結体からなり、Pc(パーミアンス係数)が2において、240kA/mの有効磁場(ただし、有効磁場=印加磁場−反磁場)を印加したときのトータルフラックスをf1、800kA/mの有効磁場を印加したときのトータルフラックスをf2、2000kA/mの有効磁場を印加したときのトータルフラックスをf3とすると、着磁率a(=f1/f3×100)が40%以上、かつ、着磁率b(=f2/f3×100)が90%以上であることを特徴とするR−T−B系希土類永久磁石。 【選択図】 図1
<P>PROBLEM TO BE SOLVED: To provide an R-T-B system rare earth permanent magnet which achieves a high magnetization rate in a low magnetizing field with its magnetization characteristics curve found in a lower magnetizing field/higher magnetization rate range. <P>SOLUTION: The R-T-B system rare earth permanent magnet is a sintered body comprising a main phase comprising an R<SB>2</SB>T<SB>14</SB>B phase (wherein R denotes one or more rare earth elements including Y and T denotes one or more transition metal elements essentially comprising Fe, or Fe and Co) and a grain boundary phase containing more R than the main phase does. Where Pc (permeance coefficient) is 2, provided that f1 is the total flux generated upon application of an effective magnetic field of 240 kA/m (wherein effective magnetic field=applied field-demagnetizing field), that f2 is the total flux generated upon application of an effective magnetic field of 800 kA/m, and that f3 is the total flux generated upon application of an effective magnetic field of 2,000 kA/M, the magnetization rate a (=f1/f3×100) is 40% or higher and the magnetization rate b (=f2/f3×100) is 90% or higher. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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Cited By (8)

    Publication numberPublication dateAssigneeTitle
    JP-2006219723-AAugust 24, 2006Tdk Corp, Tdk株式会社R-Fe-B-BASED RARE EARTH PERMANENT MAGNET
    JP-2006278990-AOctober 12, 2006Tdk Corp, Tdk株式会社希土類永久磁石
    JP-2006295140-AOctober 26, 2006Tdk Corp, Tdk株式会社希土類永久磁石
    JP-2009231391-AOctober 08, 2009Hitachi Metals Ltd, 日立金属株式会社R−t−b系焼結磁石
    JP-2011216726-AOctober 27, 2011Nitto Denko Corp, 日東電工株式会社R−t−b系永久磁石
    JP-4529180-B2August 25, 2010Tdk株式会社希土類永久磁石
    KR-101227273-B1January 28, 2013신에쓰 가가꾸 고교 가부시끼가이샤Nd-Fe-B based Rare-Earth Permanent Magnet Material
    WO-2006054617-A1May 26, 2006Tdk CorporationRare earth sintered magnet