1、 IEC/TR 62518 Edition 1.0 2009-03 TECHNICAL REPORT Rare earth sintered magnets Stability of the magnetic properties at elevated temperatures IEC/TR 62518:2009(E) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2009 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part o
2、f this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IECs member National Committee in the country of the requester. If you have any questions about IEC copyright
3、 or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information. Droits de reproduction rservs. Sauf indication contraire, aucune partie de cette publication ne peut tre reproduite ni util
4、ise sous quelque forme que ce soit et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de la CEI ou du Comit national de la CEI du pays du demandeur. Si vous avez des questions sur le copyright de la CEI ou si vous dsirez obtenir des droits suppl
5、mentaires sur cette publication, utilisez les coordonnes ci-aprs ou contactez le Comit national de la CEI de votre pays de rsidence. IEC Central Office 3, rue de Varemb CH-1211 Geneva 20 Switzerland Email: inmailiec.ch Web: www.iec.ch About IEC publications The technical content of IEC publications
6、is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigenda or an amendment might have been published. Catalogue of IEC publications: www.iec.ch/searchpub The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, t
7、echnical committee,). It also gives information on projects, withdrawn and replaced publications. IEC Just Published: www.iec.ch/online_news/justpub Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available on-line and also by email. E
8、lectropedia: www.electropedia.org The worlds leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical Vocabulary online. Custom
9、er Service Centre: www.iec.ch/webstore/custserv If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service Centre FAQ or contact us: Email: csciec.ch Tel.: +41 22 919 02 11 Fax: +41 22 919 03 00 IEC/TR 62518 Edition 1.0 2009-03 TECHNICAL RE
10、PORT Rare earth sintered magnets Stability of the magnetic properties at elevated temperatures INTERNATIONAL ELECTROTECHNICAL COMMISSION U ICS 29.030 PRICE CODE ISBN 2-8318-1034-1 Registered trademark of the International Electrotechnical Commission 2 TR 62518 IEC:2009(E) CONTENTS FOREWORD.4 INTRODU
11、CTION.6 1 Scope.7 2 Normative references .7 3 Terms and definitions .7 4 Classification of magnetic flux loss due to temperature.9 4.1 Reversible flux loss .9 4.2 Irreversible flux loss 9 4.3 Permanent flux loss.9 5 Long term ageing of rare earth magnets .10 6 Experimental 11 7 Temperature stability
12、13 7.1 Flux change due to temperature 13 7.2 Effect of temperature on B rand H cJ(demagnetization curves at different temperatures)14 7.3 The time effects at constant temperature (influence of temperature exposure and L/D) 16 7.4 The influence of H cJon the irreversible flux loss for Sm 2 Co 17magne
13、ts .18 7.5 The influence of H cJ on the irreversible flux loss for Nd-Fe-B magnets .20 7.6 Irreversible flux loss per decade22 7.7 Permanent flux loss.22 8 Summary24 Annex A (informative) Summary of temperature stability graphs.25 Annex B (informative) Non-linearity of temperature dependence of B ra
14、nd H cJ 26 Bibliography27 Figure 1 Change of magnetic flux density operating on a load line during elevated temperature ageing after R. Tenzer (schematic) 7, 8 10 Figure 2 Long term ageing of rare earth magnets (schematic) 9.11 Figure 3 Measuring system of open circuit flux utilizing a fluxgate type
15、 digital integrating fluxmeter 13 12 Figure 4 Temperature dependence of flux for SmCo 5magnet (L/D = 0,7) 16 (See Table 1) 14 Figure 5 Temperature dependence of flux for Sm 2 Co 17magnet (L/D = 0,7) 16 (See Table 1) 14 Figure 6 Temperature dependence of flux for Nd-Fe-B magnet (L/D = 0,7) 17 (See Ta
16、ble 1) 14 Figure 7 J-H demagnetization curves of Nd-Fe-B magnet measured at different temperatures 18 .14 Figure 8 J-H demagnetization curves of Nd-Fe-B magnet measured at different temperatures 19 .15 Figure 9 Temperature dependence of normalized B rand H cJfor SmCo 5 , Sm 2 Co 17and Nd-Fe-B magnet
17、s 1915 Figure 10 Time dependence of irreversible flux loss for SmCo 5magnet exposed at different temperatures 2216 Figure 11 Time dependence of irreversible flux loss for SmCo 5magnets with various L/Ds 24.16 TR 62518 IEC:2009(E) 3 Figure 12 Time dependence of irreversible flux loss for Sm 2 Co 17ma
18、gnet exposed at different temperatures (Material 1) 22 .17 Figure 13 Time dependence of irreversible flux loss for Sm 2 Co 17magnets with various L/Ds (Material 2) 2417 Figure 14 Time dependence of irreversible flux loss for Nd-Fe-B magnet exposed at different temperatures 2317 Figure 15 Temperature
19、 dependence of irreversible flux loss after exposure for 100 h for Nd-Fe-B magnets with various L/Ds 2517 Figure 16 Time dependence of irreversible flux loss for a Sm 2 Co 17magnet with H cJ = 0,48 MA/m and L/D = 0,7 26 19 Figure 17 Time dependence of irreversible flux loss for a Sm 2 Co 17magnet wi
20、th H cJ = 1,19 MA/m and L/D = 0,7 27 19 Figure 18 Time dependence of irreversible flux loss for a Sm 2 Co 17magnet with H cJ = 1,97 MA/m and L/D = 0,7 28 19 Figure 19 Time dependence of irreversible flux loss for a Nd-Fe-B magnet with H cJ = 1,16 MA/m and L/D = 0,7 30 20 Figure 20 Time dependence of
21、 irreversible flux loss for a Nd-Fe-B magnet with H cJ = 1,66 MA/m and L/D = 0,7 31 .20 Figure 21 Time dependence of irreversible flux loss for a Nd-Fe-B magnet with H cJ = 2,17 MA/m and L/D = 0,7 32 .21 Figure 22 Time dependence of irreversible flux loss for a Nd-Fe-B magnet with H cJ = 2,45 MA/m a
22、nd L/D = 0,7 33 .21 Figure 23 Comparison of irreversible flux loss for Sm 2 Co 17magnets with different H cJ21 Figure 24 Comparison of irreversible flux loss for Nd-Fe-B magnets with different H cJ 21 Figure 25 Relationship between irreversible flux loss per decade and initial flux loss23 Figure B.1
23、 Temperature dependence of normalized B rand H cJto show the non- linearity (see data for Nd-Fe-B magnets in Figure 9).26 Table 1 Magnetic properties of the rare earth magnets employed for the open circuit flux measurements to determine the reversible temperature coefficient of the magnetic flux 13
24、Table 2 Reversible temperature coefficient of the magnetic flux determined by temperature cycling 13 Table 3 Temperature coefficients of B rand H cJfor SmCo 5 , Sm 2 Co 17and Nd-Fe-B magnets (temperature range for the coefficient: 25 C to 150 C) .16 Table 4 Magnetic properties of the specimens for t
25、he experiments to evaluate the effects of temperature and L/D on irreversible flux loss.18 Table 5 Magnetic properties of the Sm 2 Co 17magnets for the experiment to evaluate the influence of H cJ on the irreversible flux loss .20 Table 6 The magnetic properties of Nd-Fe-B magnets for the evaluation
26、 of the influence of H cJon irreversible flux loss measured by a pulse recording fluxmeter .22 Table 7 The permanent flux loss of Sm 2 Co 17magnets after exposure for 1 000 h at different temperatures.23 Table 8 The permanent flux loss of Nd-Fe-B magnets after exposure for 1 000 h at different tempe
27、ratures.23 Table 9 Basic magnetic properties of the three intermetallic compounds24 Table A.1 Summary of temperature stability graphs .25 4 TR 62518 IEC:2009(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION _ RARE EARTH SINTERED MAGNETS STABILITY OF THE MAGNETIC PROPERTIES AT ELEVATED TEMPERATURES FOREW
28、ORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the elec
29、trical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to tec
30、hnical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non- governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Org
31、anization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technic
32、al committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publica
33、tions is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their nation
34、al and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be
35、in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committee
36、s for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the
37、 Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held
38、responsible for identifying any or all such patent rights. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a technical report when it has collected data of a different kind from that which is normally publ
39、ished as an International Standard, for example “state of the art“. IEC 62518, which is a technical report, has been prepared by IEC technical committee 68: Magnetic alloys and steels. The text of this technical report is based on the following documents: Enquiry draft Report on voting 68/376/DTR 68
40、/383/RVC Full information on the voting for the approval of this technical report can be found in the report on voting indicated in the above table. TR 62518 IEC:2009(E) 5 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that the contents
41、 of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingu
42、al version of this publication may be issued at a later date. 6 TR 62518 IEC:2009(E) INTRODUCTION SmCo 5was the first sintered rare earth magnet to be developed (1967) 1 1 , followed by Sm 2 Co 17 2, 3, 4 and Nd-Fe-B 5. These magnets are used in a wide variety of applications. Recently, these magnet
43、s have been used in higher temperature applications such as in heavy duty permanent magnet motors. For these high temperature applications, the temperature stability of the permanent magnet has to be considered along with the design of the magnetic circuit. This is particularly relevant for the rela
44、tively inexpensive Nd-Fe-B magnetic material which has a comparatively low Curie temperature. The temperature stability of the rare earth sintered magnets has a critical influence on the reliability of high temperature motors and this will, in turn, contribute to energy savings in the future. Theref
45、ore, the subject of this technical report will be of considerable interest to the manufacturers of this type of motor and to the developers of permanent magnet materials. 1The figures in square brackets refer to the Bibliography. TR 62518 IEC:2009(E) 7 RARE EARTH SINTERED MAGNETS STABILITY OF THE MA
46、GNETIC PROPERTIES AT ELEVATED TEMPERATURES 1 Scope The scope of this technical report is to describe the temperature behaviour of rare earth sintered magnets in detail for use in designing magnetic circuits exposed to elevated temperatures. The temperature behaviour of SmCo 5 , Sm 2 Co 17and Nd-Fe-B
47、 sintered magnets is described. The various changes of open circuit flux which can occur due to temperature are discussed in Clause 4. The long term stability of the magnets is discussed in Clause 5. The experimental procedures are described in Clause 6. Results of the measurements of the flux loss
48、occurring at the ambient temperature after heating isothermally at 50 C, 75 C, 100 C, 125 C, 150 C and 200 C for up to 1000 h are given in Clause 7. The effect of length to diameter ratio (L/D) of the magnet samples and the influence of H cJon the flux loss were also studied. The results are discuss
49、ed in Clause 8. The data in this technical report was provided by the Institute of Electrical Engineers of Japan (IEEJ) and its subcommittees. This data has been gathered from the members of these sub- committees. The temperature stability correlated with the complex corrosion behaviour and the spin re- orientation phenomena at cryogenic temperatures
