I E C 60 40 4-1 ® I N TE RN ATI ON AL S TAN D ARD M ag n eti c m ateri al s – IEC 60404-1 :201 6-1 0(en) P art : C l as s i fi cati on Edition 3.0 201 6-1 T H I S P U B L I C AT I O N I S C O P YRI G H T P RO T E C T E D C o p yri g h t © I E C , G e n e v a , S wi tz e rl a n d All rights reserved Unless otherwise specified, no part of 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 IEC's member National Committee in the country of the requester If you have any questions about I EC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local I EC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Ab ou t th e I E C The I nternational Electrotechnical Commission (I EC) is the leading global organization that prepares and publishes I nternational Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i ca ti o n s The technical content of IEC publications 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 I E C Catal og u e - webstore i ec ch /catal og u e The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad I E C pu bl i cati on s s earch - www i ec ch /search pu b The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications E l ectroped i a - www el ectroped i a org The world's leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C G l os sary - s td i ec ch /g l oss ary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u st Pu bl i s h ed - webstore i ec ch /j u stpu bl i sh ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email I E C C u stom er S ervi ce C en tre - webstore i ec ch /csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C 60 40 4-1 ® Edition 3.0 201 6-1 I N TE RN ATI ON AL S TAN D ARD M ag n e ti c m ateri al s – P art : C l as s i fi cati on INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.030 ISBN 978-2-8322-3671 -0 Warn i n g ! M ake s u re th a t you ob tai n ed th i s p u b l i cati on from an au th ori zed d i stri b u tor ® Registered trademark of the International Electrotechnical Commission –2– I EC 60404-1 : 201 © I EC 201 CONTENTS FOREWORD Scope Norm ative references Terms and definitions Magneticall y soft materials (coercivity ≤ kA/m) Class A – I rons Reference documents Chemical composition Basis of subclassification Available forms Ph ysical characteristics Main applications Class B – Low carbon mild steels Class B1 – Bulk material 2 Class B2 – Flat material Class C – Silicon steels Class C1 – Bulk m aterial Class C2 – Flat m aterial 1 4 Class D – Other steels 4 Class D1 – Bulk m aterial 4 Class D2 – Flat m aterial 4 Class D3 – Stainless steels Class E – Nickel-iron alloys Class E1 – N ickel content 70 % to 85 % Class E2 – N ickel content 54 % to 68 % 20 Class E3 – N ickel content 40 % to 51 % 21 Class E4 – N ickel content 35 % to 40 % 22 5 Class E5 – N ickel content 29 % to 33 % 23 Class F – I ron-cobalt alloys 24 Class F1 – Cobalt content 47 % to 50 % 24 Class F2 – Cobalt content 35 % 24 Class F3 – Cobalt content 23 % to 30 % 25 Class G – Other alloys 26 Class G1 – Aluminium -iron alloys 26 Class G2 – Aluminium -silicon-iron alloys 27 Class H – M agnetically soft materials m ade by powder metallurgical techniques 27 Class H – Soft ferrites 27 Class H – M agnetically soft sintered materials 29 Class H – Powder com posites 29 Class I – Am orphous soft m agnetic materials 30 General 30 Class I – I ron-based am orphous alloys 30 Class I – Cobalt-based am orphous alloys 31 Class I – N ickel-based am orphous alloys 32 Class J – Nano-crystalline soft m agnetic materials 33 I EC 60404-1 : 201 © I EC 201 –3– 1 Reference document 33 Production process 33 Chemical composition 33 4 Basis of subclassification 33 Available forms 33 Ph ysical characteristics 33 Main applications 34 Magneticall y hard m aterials (coercivity > kA/m ) 34 Class Q – Magnetostrictive alloys – Rare earth iron alloys (Class Q1 ) 34 Reference document 34 Chemical composition 34 Basis of subclassification 34 Available forms 34 Ph ysical characteristics 34 Main applications 35 Class R – M agnetically hard alloys 35 Class R1 – Alum inium -nickel-cobalt-iron-titanium (AlN iCo) alloys 35 2 Class R3 – I ron-cobalt-vanadium -chromium (FeCoVCr) alloys 36 Class R5 – Rare earth cobalt (RECo) alloys 36 Class R6 – Chromium -iron-cobalt (CrFeCo) alloys 37 5 Class R7 – Rare earth-iron-boron (REFeB) alloys 38 Class S – Magnetically hard ceram ics – H ard ferrites (Class S1 ) 39 Reference document 39 Chemical composition and m anufacturing method 39 3 Basis of subclassification 39 Available forms 39 5 Ph ysical characteristics 40 Main applications 40 Class T – Other magneticall y hard m aterials – Martensitic steels (Class T1 ) 40 Reference document 40 Composition 40 Basis of subclassification 40 4 Available forms 40 5 Ph ysical characteristics 40 Main applications 41 5 Class U – Bonded m agneticall y hard materials 41 5 General 41 5 Class U – Bonded alum inium -nickel-cobalt-iron-titanium (AlNiCo) magnets 41 5 Class U – Bonded rare earth-cobalt (RECo) m agnets 42 5 Class U – Bonded neodym ium -iron-boron (REFeB) m agnets 42 5 Class U – Bonded hard ferrite magnets 43 5 Class U – Bonded rare earth-iron-nitrogen magnets 44 –4– I EC 60404-1 : 201 © I EC 201 INTERNATI ONAL ELECTROTECHNI CAL COMMISSI ON M AG N E T I C M AT E RI AL S – P a rt : C l a s s i fi c a ti o n FOREWORD ) The I nternati on al Electrotechni cal Comm ission (I EC) is a worl d wid e organization for stan dardization com prisin g all n ation al el ectrotechnical comm ittees (I EC National Comm ittees) The object of I EC is to prom ote internati onal co-operation on all q uestions concerni ng stand ardi zati on in the el ectrical an d electronic fi elds To this en d and in additi on to other acti vities, I EC pu blish es I nternational Stan dards, Techn ical Specificati ons, Technical Reports, Publicl y Avail abl e Specificati ons (PAS) an d Gu ides (h ereafter referred to as “I EC Publication(s)”) Th ei r preparation is entrusted to tech nical comm ittees; any I EC N ational Comm ittee interested in the subj ect dealt with m ay partici pate in this preparatory work I nternational, governm ental an d n on governm ental organ izations l iaising with th e I EC also participate i n this preparation I EC collaborates closel y with the I ntern ational Organi zation for Stand ardization (I SO) in accordance with ditions determ ined by agreem ent between th e two organi zati ons 2) The form al decisions or ag reem ents of I EC on tech nical m atters express, as n early as possible, an i nternati onal consensus of opi nion on the rel evant subjects since each technical com m ittee has representati on from all interested I EC N ational Com m ittees 3) I EC Publications have the form of recom m endations for intern ational use an d are accepted by I EC National Com m ittees in that sense While all reasonable efforts are m ade to ensure that th e technical content of I EC Publications is accu rate, I EC cann ot be h eld responsi ble for th e way in which th ey are used or for an y m isinterpretation by an y en d u ser 4) I n order to prom ote intern ational u niform ity, I EC National Com m ittees und ertake to apply I EC Publications transparentl y to the m axim um extent possible i n their national an d regi on al publicati ons Any d ivergence between an y I EC Publication and the correspondi ng national or regi on al publicati on sh all be clearl y in dicated in the latter 5) I EC itself d oes n ot provi de an y attestation of conform ity I n depend ent certificati on bodies provi de conform ity assessm ent services and, in som e areas, access to I EC m arks of conform ity I EC is not responsi ble for any services carri ed out by ind ependent certification bodi es 6) All users shou ld ensure that th ey have the l atest editi on of thi s publicati on 7) No liability shall attach to I EC or its directors, em ployees, servants or ag ents inclu din g in divi dual experts an d m em bers of its technical com m ittees and I EC Nati on al Com m ittees for any person al i nju ry, property d am age or other dam age of any nature whatsoever, wheth er di rect or indirect, or for costs (includ i ng leg al fees) and expenses arisi ng out of the publ ication, use of, or relian ce upon, this I EC Publicati on or any other I EC Publications 8) Attention is drawn to th e N orm ative references cited in th is publ ication Use of the referenced publ ications is indispensable for the correct applicati on of this publication 9) Attention is drawn to the possibility that som e of the elem ents of this I EC Publication m ay be the su bject of patent rig hts I EC shall not be held responsibl e for identifyi ng any or all such patent ri ghts I nternational Standard I EC 60404-1 has been prepared by I EC technical comm ittee 68: Magnetic alloys and steels This third edition cancels and replaces the second edition published in 2000 and constitutes a technical revision This edition includes the following significant technical changes with respect to the previous edition: a) Rem oval of all tables and values describing typical properties of the m aterial to be consistent with the aim of the document to be a classification and not a specification b) Enlargement of the N i content for the classes E1 and E3 c) Enlargement of the Co content for the classes F3 d) Addition of a new class: U5 bonded rare earth-iron-nitrogen m agnets I EC 60404-1 : 201 © I EC 201 –5– The text of this standard is based on the following documents: CDV Report on votin g 68/533/CDV 68/555/RVC Full information on the voting for the approval of this I nternational Standard can be found in the report on voting indicated in the above table This docum ent has been drafted in accordance with the I SO/I EC Directives, Part A list of all parts in the I EC 60404 series, published under the general title materials , can be found on the I EC website Magnetic The com mittee has decided that the contents of this document will remain unchanged until the stability date indicated on the I EC website under "http://webstore iec ch" in the data related to the specific docum ent At this date, the document will be • • • • reconfirmed, withdrawn, replaced by a revised edition, or am ended A bilingual version of this publication m ay be issued at a later date –6– I EC 60404-1 : 201 © I EC 201 M AG N E T I C M AT E RI AL S – P a rt : C l a s s i fi c a ti o n S cop e This part of I EC 60404 is intended to classify comm erciall y available m agnetic materials The term "magnetic m aterials" denotes substances where the application requires the existence of ferromagnetic or ferrim agnetic properties I n this document, the classification of magnetic m aterials is based upon the generall y recognized existence of two main groups of products: • • soft m agnetic materials (coercivity ≤ 000 A/m); hard m agnetic materials (coercivity > 000 A/m ) Within these m ain groups, the classification when appropriate recognizes the following characteristics: • • the m ain alloying elem ent and the metallurgical state and ph ysical properties of the m aterial; when possible and convenient, the relationship between these characteristics is identified A classification by specific areas of application cannot be applied to all m aterials because different m aterials can very often be used for the same application depending on the characteristics required N o rm a t i ve re fe re n c e s The following docum ents are referred to in the text in such a way that some or all of their content constitutes requirements of this docum ent For dated references, onl y the edition cited applies For undated references, the latest edition of the referenced docum ent (including an y am endm ents) applies I EC 60050-1 21 , International Electrotechnical Vocabulary – Part 121: Electromagnetism I EC 60050-1 51 , International Electrotechnical Vocabulary – Part 151: Electrical and magnetic I EC 60050-221 , International Electrotechnical Vocabulary – Chapter 221: Magnetic materials devices and components Terms and nomenclature for cores made of magnetically soft ferrites – Part 3: Guidelines on the format of data appearing in manufacturers catalogues of transformer and inductor cores I EC 60401 -3, I EC 60404-2, Magnetic materials – Part 2: Methods of measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame I EC 60404-3, Magnetic materials – Part 3: Methods of measurement of the magnetic properties of magnetic sheet and strip by means of a single sheet tester I EC 60404-1 : 201 © I EC 201 –7– IEC 60404-4, Magnetic materials – Part 4: Methods of measurement of d.c magnetic properties of iron and steel I EC 60404-6, Magnetic materials – Part 6: Methods of measurement of the magnetic properties of magnetically soft metallic and powder materials at frequencies in the range 20 Hz to 200 kHz by the use of ring specimens Magnetic materials – Part 7: Method of measurement of the coercivity of magnetic materials in an open magnetic circuit I EC 60404-7, I EC 60404-8-1 , Magnetic materials – Part 8-1: Specifications for individual materials – Magnetically hard materials Magnetic materials – Part 8-3: Specifications for individual materials – Coldrolled electrical non-alloyed and alloyed steel sheet and strip delivered in the semi-processed state I EC 60404-8-3, I EC 60404-8-4, Magnetic materials – Part 8-4: Specifications for individual materials – Coldrolled non-oriented electrical steel strip and sheet delivered in the fully-processed state I EC 60404-8-5, Magnetic materials – Part 8: Specifications for individual materials – Section Five: Specification for steel sheet and strip with specified mechanical properties and magnetic permeability Magnetic materials – Part 8-6: Specifications for individual materials – Soft magnetic metallic materials I EC 60404-8-6, I EC 60404-8-7, Magnetic materials – Part 8-7: Specifications for individual materials –Coldrolled grain-oriented electrical steel strip and sheet delivered in the fully processed state I EC 60404-8-8, Magnetic materials – Part 8: Specifications for individual materials – Section 8: Specification for thin magnetic steel strip for use at medium frequencies I EC 60404-8-9, Magnetic materials – Part 8: Specifications for individual materials – Section 9: Standard specification for sintered soft magnetic materials Magnetic materials – Part 8-10: Specifications for individual materials – Magnetic materials (iron and steel) for use in relays I EC 60404-8-1 0, I EC 60404-1 0, Magnetic materials Part 10: Methods of measurement of magnetic properties of magnetic sheet and strip at medium frequencies I SO 4948-1 , Steels – Classification – Part 1: Classification of steels into unalloyed and alloy steels based on chemical composition Terms and definitions For the purposes of this docum ent, the term s and definitions given in I EC 60050-1 21 , I EC 60050-1 51 , I EC 60050-221 and in the product standards of the I EC 60404-8 series apply ISO and I EC m aintain terminological databases for use in standardization at the following addresses: • • I EC Electropedia: available at http: //www electropedia.org/ I SO Online browsing platform: available at http://www iso.org/obp –8– M a g n e t i c a l l y s o ft m a t e ri a l s ( c o e rc i vi t y Cl ass ≤1 I EC 60404-1 : 201 © I EC 201 k A/ m ) A – I ro n s R e fe re n c e d o c u m e n t s These m aterials are covered by I EC 60404-8-6 and I EC 60404-8-1 C h em i cal c o m p o s i ti o n The basic constituent of these m aterials is pure iron, and they are often referred to as "commerciall y pure" or "magneticall y soft" irons The m aterial also tains unavoidable impurities that m ay affect m agnetic properties The am ount of impurities that adversel y affect the remanence, coercivity, saturation, magnetic polarization and stability of the magnetic properties are lim ited to produce the required m agnetic properties for the proposed application For inform ation the most significant impurities when they are present in these materials are carbon (up to 0, 03 %), silicon (up to 0, %), m anganese (up to 0, %), phosphorus (up to 0, 01 %), sulphur (up to 0,03 %), alum inium (up to 0,08 %), titanium (up to 0, %) and vanadium (up to 0, %) NOTE For im proved free m achini ng capability, the am ou nt of phosph orus and sulphu r can be hi gher than indicated above B a s i s o f s u b c l a s s i fi c a t i o n The recomm ended subclassification is based on coercivity values Av a i l a b l e fo rm s These m aterials are available in a wide variety of form s They m ay be supplied as slabs, billets, ingots or forgings; as hot-rolled bar in rectangular and square cross-sections; as hotrolled wire rod in round, hexagonal and octagonal cross-sections; in cold-rolled and drawn form s as bar and wire; as hot- or cold-rolled sheet and strip P h ys i ca l c h a c t e ri s t i c s I n addition to the values of coercivity, a m ore complete definition of these materials can be based on the following characteristics: • m agnetic: • m echanical: • m etallurgical state: saturation m agnetic polarization, m agn etic polarization at various values of m agnetic field strength (from which perm eability can be derived), stability of characteristics with tim e; hardness, suitability for punching operations, free machining capability, deep drawing properties, tensile strength; hot- or cold-worked, forged, deep drawn, full y processed state, i e final annealed NOTE For m aterial not deli vered in th e full y processed state, subclassification is based on th e coercivity m easured after h eat treatm ent accordin g to the req ui rem ents of the product stand ard or the recomm endations of the m anufacturer Ranges of specified values for the above-m entioned m agnetic characteristics in the full y processed state are given in the corresponding product specifications M n ap pl i cati on s The m ain applications are in DC relays, loudspeakers, electromagnets, magnetic clutches, brakes, parts for magnetic circuits in instrum ents and control apparatus, as well as for pole pieces and other DC parts for generators and m otors – 32 – • • • • electrical: therm al: dim ensions: m etallurgical state: I EC 60404-1 : 201 © I EC 201 resistivity; Curie temperature, crystallization temperature; thickness, width; sem i-processed state, i e as cast The properties depend strongly on the exact composition of the m aterial and on the heat treatm ent Some m agnetic properties can be developed by further heat treatment with or without a magnetic field M n appl i cati on s Variation of one property norm all y influences the value of various other properties This situation gives rise to the existence of many different m aterials, each intended for a relatively small group of applications The m ost im portant ones are • • • • cores for inductors and transformers operating at frequencies in the range from 50 H z to several MH z, cores for pulse transform ers, cores for recording heads, and flexible magnetic shielding 4 C l a s s I – N i c ke l -b a s e d a m o rp h o u s a l l o y s R e fe re n c e d o c u m e n t These m aterials are not covered by an I EC publication C h em i cal c o m p o s i ti o n The basic metallic constituents of these m aterials are nickel and iron in approximatel y equal am ounts by weight and which form about 90 % of the alloy by weight I n som e alloys molybdenum can be present The principal m etalloid is boron although phosphorus and silicon can also be present B a s i s o f s u b c l a s s i fi c a t i o n The recommended subclassification is based on the shape of the h ysteresis loop Av a i l a b l e fo rm s The m aterials are normall y supplied in the form of rapidl y solidified thin strips with a typical thickness of µm to 50 µm P h ys i ca l c h a c t e ri s t i c s A more com plete definition can be based on the following characteristics: • m agnetic: • electrical: therm al: dim ensions: • • magnetostriction, initial perm eability, reversible perm eability at various values of m agnetic field strength, specific total loss as a function of frequency, squareness of the B-H loop, coercivity, shielding attenuation ratio; resistivity; Curie temperature, crystallization temperature; thickness, width; I EC 60404-1 : 201 © I EC 201 • m etallurgical state: – 33 – sem i-processed state, i e as cast The properties depend strongly on the exact composition of the m aterial and on the heat treatm ent Some m agnetic properties can be developed by further heat treatment with or without a magnetic field 4.9.4.6 Main applications The m ain applications are for article surveillance sensors and m agnetic EMI shielding 4.1 Class J – Nano-crystalline soft magnetic materials 4.1 0.1 Reference document These m aterials are not covered by an I EC publication 4.1 0.2 Production process Iron-based nano-crystalline alloys are produced via rapid solidification by casting as thin sheets, wires or powders After this casting process the m aterial is in the amorphous state The desirable nano-crystalline state is achieved by annealing at temperature between 500 °C and 600 °C N ano-crystalline alloys exhibit a high saturation m agnetic polarization and an alm ost zero magnetostriction due to their nano-crystalline m icrostructure 4.1 0.3 Chemical composition The basic constituents of these m aterials are iron, copper typicall y around % by atoms, niobium around % by atom s and metalloids (mainl y silicon and boron) typicall y in the range of % by atom s to 28 % by atoms These alloys m ay further contain additions of zirconium , molybdenum , tantalum , titanium, vanadium, phosphorus, chrom ium, m anganese and carbon to improve the magnetic and mechanical properties 4.1 0.4 Basis of subclassification The recom mended subclassification is based on the saturation m agnetic polarization and the shape of the h ysteresis loop 4.1 0.5 Available forms The materials can be supplied in the am orphous state in the form of rapidl y solidified thin ribbons of typical thickness µm to 30 µm and in the nanocrystalline state in the form of tape wound cores 4.1 0.6 Physical characteristics A m ore complete definition can be based on the following characteristics: • m agnetic: • electrical: thermal: • • • dim ensions: m echanical: specific total loss as a function of m agnetic polarization and frequency, specific apparent power, saturation magnetic polarization, magnetostriction, coercivity, initial perm eability, reversible permeability at various values of magnetic field strength, squareness of the B-H loop, rem anence; resistivity; Curie tem perature, crystallization temperature of the nanocrystalline grains, crystallization temperature of the am orphous matrix; thickness, width; ductility, stacking factor; – 34 – • m etallurgical state: I EC 60404-1 : 201 © I EC 201 sem i-processed state, i e as cast The magnetic properties are developed by the heat treatm ent above the crystallisation tem perature Magnetic fields can be used to support the formation of induced anisotropies The properties depend strongly on the exact composition of the m aterial and on the heat treatm ent 4.1 0.7 Main applications Variation of one property normall y influences the value of various other properties This situation gives rise to the existence of m any different materials, each intended for a relativel y small group of applications The m ost im portant ones are • • • m agnetic cores, inductive com ponents like current transformers and yokes, shielding foils Magnetically hard materials (coercivity > kA/m) 5.1 Class Q – Magnetostrictive alloys – Rare earth iron alloys (Class Q1 ) 5.1 Reference document These m aterials are not covered by an I EC publication 5.1 Chemical composition The basic constituents of these materials are iron, terbium and d ysprosium I n Tb x Dy(1 - x ) Fe y com pounds, the value of x determines the Tb/Dy ratio and y is the Fe/(Tb + Dy) ratio The optimum values of x are close to 0, 3, where high m agnetostriction is obtained without excessive h ysteresis losses The stoichiometric value for y = 2, produces optim um magnetostrictive properties but the resulting m aterials are very brittle As y is decreased from 2, the m aterial becom es less brittle and the value of y = , 95 provides a good com prom ise 5.1 Basis of subclassification There is no recognized subclassification 5.1 Available forms Grain-oriented, round bars of different sizes are available manufactured by free stand zone melting or modified Bridgeman solidification processes The cylinder axis is the easy direction of m agnetization 5.1 Physical characteristics A m ore complete definition can be based on the following characteristics: • m agnetic: • m echanical: • thermal: magnetostrictive strain at saturation, Curie temperature, magnetoelastic coupling factor k33 , d-constant (d λ /d H), relative perm eability, magnetic specific acoustic im pedance, energ y density; density, modulus of elasticity, sound speed, tensile strength, com pressive strength; thermal expansion coefficient; I EC 60404-1 : 201 â I EC 201 ã ã electrical: m etallurgical state: – 35 – resistivity; grain-oriented and heat-treated The machinability is limited due to their brittleness The m aterials can be ground or cut by means of a spark cutter or a diamond wheel 5.1 Main applications The materials are of prim e interest for applications involving large forces and fast, highprecision motion at high power levels Such applications are in high-power sound projectors in sonars and defence systems, for oil field logging and oceanograph y studies Other applications being developed are as active elem ents in electrom echanical applications 5.2 Class R – Magnetically hard alloys 5.2.1 5.2.1 Class R1 – Aluminium-nickel-cobalt-iron-titanium (AlNiCo) alloys Reference document These m aterials are covered by I EC 60404-8-1 5.2.1 Chemical composition and manufacturing method These alloys consist of % to % aluminium , % to 28 % nickel, % to 42 % cobalt, % to % titanium, % to % copper, % to % niobium , % to 0, % silicon and the balance iron They m ay contain other additions They are m ade by casting or a powder m etallurgical process The magnetic performance of alloys with a cobalt content higher than 20 % can be increased in a preferred direction by appl ying a m agnetic field during heat treatment producing m agnetic anisotropy The best performances of cast magnets are achieved with alloys of colum nar or single crystal structure, the m agnetic field being applied parallel to the colum nar axis 5.2.1 Basis of subclassification The subclassification is based on the magnetic degree of anisotropy and the manufacturing method 5.2.1 Available forms The magnets are m ainly produced in the form of rings, prisms, cubes, cylinders or arc segments Cast m agnets with columnar or single crystal structure are subj ect to limitations of form and dim ensions 5.2.1 Physical characteristics I n addition to the degree of anisotropy and the manufacturing m ethod, a more complete definition can be based on the following characteristics: • m agnetic: • therm al: • m echanical: m etallurgical state: dim ensions: • • maxim um BH product, rem anent flux density, coercivity, recoil perm eability; tem perature coefficients of rem anent flux density and of coercivity, and Curie temperature; density, m achinability; cast or sintered and heat-treated; determ ined by application – 36 – I EC 60404-1 : 201 © I EC 201 Ranges of specified values of magnetic properties and density for isotropic and anisotropic AlN iCo alloys are given in the corresponding product specification M n a ppl i cati on s These m aterials are used in measuring devices and loudspeakers C l a s s R – I ro n - c o b a l t - v a n a d i u m - c h ro m i u m ( F e C o V C r) a l l o y s Re fe re n c e d o c u m e n t These m aterials are covered by I EC 60404-8-1 Ch em i cal c o m p o s i ti o n an d m a n u fa c t u ri n g m eth od These materials consist of 49 % to 54 % cobalt, % to % vanadium plus chromium and the balance being iron The FeCoVCr alloys are manufactured by casting and subsequent hot and cold rolling or drawing to produce strips or wires, respectivel y B a s i s o f s u b c l a s s i fi c a t i o n The recommended subclassification is based on the coercivity HcJ Av a i l a b l e fo rm s The material is generally available in the form of wires and bars with diameter strips with a thickness < mm P h ys i ca l < 20 m m or c h a c t e ri s t i c s A more complete definition of these magneticall y anisotropic m aterials can be based on the following characteristics: • magnetic: • therm al: • mechanical: metallurgical state: dimensions: • • maximum BH product, remanent flux density, coercivity; tem perature coefficients of rem anent flux density and of coercivity, and Curie tem perature; machinability before hardening; hot- and cold-rolled, heat-treated to develop m agnetic properties; determ ined by application Specified values of magnetic properties and density for final annealed anisotropic FeCoVCr alloys are given in the corresponding product specification M n app l i cati on s These m aterials are used for com pass needles, h ysteresis motors, speedom eters and sensors, and actuators for electrom echanical displays 5 C l a s s R – R a re e a rt h c o b a l t ( RE C o ) a l l o ys R e fe re n c e d o c u m e n t These m aterials are covered by I EC 60404-8-1 I EC 60404-1 : 201 © I EC 201 5.2.3.2 – 37 – Chemical composition and manufacturing method Two main types of RECo m agnet m aterial are available; they are based on the com pounds Sm Co and Sm Co The Sm Co alloys consist of 33 % to 36 % sam arium and the balance cobalt The Sm Co alloys consist of 24 % to 26 % sam arium , % to 20 % iron, 4, % to % copper, other elements (e.g zirconium , hafnium or titanium ) and the balance cobalt Magnets may be formed by compacting the powder in a m agnetic field and sintering the compacted bod y followed by heat treatm ents 5.2.3.3 Basis of subclassification The recomm ended subclassification is based on chemical com position and manufacturing method 5.2.3.4 Available forms The materials are typically available in the form of blocks, cylinders, rings and arc segments 5.2.3.5 Physical characteristics All RECo m agnetic materials are normall y magneticall y anisotropic A more com plete definition can be based on the following characteristics: • magnetic: • therm al: • mechanical: metallurgical state: dimensions: • • m aximum BH product, rem anent flux density, coercivity, recoil permeability, uniform ity field strength; temperature coefficients of remanent flux density and of coercivity, and Curie temperature; density, machinability; sintered; determined by application Sintered materials are brittle but m achinable by grinding Ranges of specified values of m agnetic properties and density for anisotropic sintered RECo alloys are given in the corresponding product specification I n addition, materials with im proved m agnetic properties, especiall y HcJ , are available 5.2.3.6 Main applications These m aterials are m ainl y used in rotating machin es and m an y other motor applications, transducers, separators, magnetic clutches and for m edical applications They find particular application where miniaturization is a requirem ent 5.2.4 5.2.4.1 Class R6 – Chromium-iron-cobalt (CrFeCo) alloys Reference document These m aterials are covered by I EC 60404-8-1 5.2.4.2 Chemical composition and manufacturing method The m aterials consist of 25 % to 35 % chromium , % to 25 % cobalt, 0, % to % other elements (e g silicon, titanium, mol ybdenum, alum inium and vanadium) and the bal ance iron The CrFeCo alloys can be m anufactured by casting, followed by hot and cold rolling and drawing to produce strips and wires The m agnets can also be form ed by a powder – 38 – I EC 60404-1 : 201 © I EC 201 metallurgical process The magnetic performance of the cast as well as sintered material can be increased in a preferred direction by appl ying a m agnetic field during heat treatm ent 5.2.4.3 Basis of su bclassification The recomm ended subclassification is based on the degree of magnetic anisotropy and the manufacturing m ethod (cast or sintered) 5.2.4.4 Available forms The materials are generall y available in the form of wire, strip and rod They are also available in the form of cast shapes 5.2.4.5 Physical characteristics A m ore complete definition of these materials can be based on the following characteristics: • m agnetic: • therm al: • m echanical: m etallurgical state: dim ensions: • • maxim um BH product, remanent flux density, coercivity, recoil perm eability; tem perature coefficients of remanent flux density and of coercivity, and Curie temperature; machinability and workability; cold-rolled or drawn, cast, sintered; determ ined by application Ranges of specified values of m agnetic properties and density for final annealed isotropic and anisotropic CrFeCo alloys are given in the corresponding product specification 5.2.4.6 M ain applications These m aterials are used for m easuring devices, loudspeakers, rotating machines (including h ysteresis motors), speedom eters and theft detection labels and tags 5.2.5 5.2.5.1 Class R7 – Rare earth-iron-boron (REFeB) alloys Reference document These m aterials are covered by I EC 60404-8-1 5.2.5.2 Chemical composition and manufacturing method The alloys are based on the com pound RE Fe B RE is m ainl y neod ym ium , which m ay be partiall y substituted by dysprosium, praseod ym ium or other rare earths I ron may be partiall y substituted by cobalt The alloys consist of 28 % to 35 % total rare earth, % to 5% cobalt 0, 85 % to , % boron, % to 0% d ysprosium, terbium and praseodym ium , % to % vanadium, niobium , aluminium , gallium and copper, the balance iron Magnets of this type can be divided into two main groups: • • the first group is prepared by compacting milled alloy powder in a m agnetic field and sintering the compacted bod y for densification followed by a heat treatment, resulting in a m agnet with anisotropic m agnetic properties; the second group uses rapidl y solidified flakes prepared by the m elt-spinning process Three different products are obtained by processing the flakes into an isotropic resinbonded magnet (see 5.4), an isotropic hot-pressed m agnet and a magnet with anisotropic m agnetic properties achieved by hot die upset forging or extrusion A metallic or resinous layer on the surface of the m agnet m ay be applied to resist corrosive attacks I EC 60404-1 : 201 © I EC 201 5.2.5.3 – 39 – Basis of subclassification The recom mended subclassification is based on the degree of m agnetic anisotropy of the material and the m anufacturing m ethod 5.2.5.4 Available forms The m aterials are typically available in the form of blocks, cylinders, rings and arc segm ents 5.2.5.5 Physical characteristics A m ore com plete definition of these materials can be based on the following characteristics: • m agnetic: • therm al: • m echanical: dim ensions: • maxim um BH product, remanent flux density, coercivity, recoil perm eability, dem agnetization field strength; tem perature coefficients of remanent flux density and of coercivity, and Curie temperature; density, m achinability; determ ined by application Sintered or hotpressed materials are brittle, but machinable by grinding Ranges of specified values of m agnetic properties and density for anisotropic sintered REFeB alloys are given in the corresponding product specification 5.2.5.6 Main applications The materials are mainly used for traction m otors for h ybrid electric vehicles (HEV) and electric vehicles (EV), direct drive type generators for wind turbines, voice coil motors and many other electrical m otors, electroacoustical applications, separators, magnetic resonance imaging (MRI ) 5.3 5.3.1 Class S – Magnetically hard ceramics – Hard ferrites (Class S1 ) Reference document These materials are covered by I EC 60404-8-1 5.3.2 Chemical composition and manufacturing method The composition of the hard ferrites can be described by the formula MO· n Fe (where M is barium or strontium) The value of n can vary from 4, to 6, The m agnetic properties m ay be im proved by special substitutions This is particularl y so with substitutions of up to % of lanthanum and up to % of cobalt The hard ferrites have a hexagonal structure crystal with magnetic anisotropy Compacting of the powder is carried out with or without a magnetic field, thus obtaining anisotropic or isotropic m agnets The pressed bodies are sintered 5.3.3 Basis of subclassification The recom mended subclassification is based on the degree of magnetic anisotropy and the manufacturing method 5.3.4 Available forms Magnetic isotropic and anisotropic sintered hard ferrites are m ainl y produced as rings, prism atic blocks, cylinders and arc segments – 40 – 5.3.5 I EC 60404-1 : 201 © I EC 201 Physical characteristics A m ore com plete definition of these m aterials can be based on the following characteristics: • m agnetic: • thermal: • m echanical: dim ensions: • m axim um BH product, remanent flux density, coercivity, recoil perm eability; tem perature coefficients of remanent flux density and of coercivity, and Curie tem perature; density, m achinability, m echanical strength; determined by application Sintered materials are brittle, but m achinable by grinding Sintered m agnets have usuall y large transverse dimensions com pared with their length Ranges of specified values of magnetic properties and density for isotropic and anisotropic hard ferrites are given in the corresponding product specification 5.3.6 Main applications The m aterials are mainly used in rotating machines, loudspeakers, holding devices and toys 5.4 Class T – Other magnetically hard materials – Martensitic steels (Class T1 ) 5.4.1 Reference document These m aterials are not covered by an I EC publication 5.4.2 Composition These materials have a tetragonal structure which is achieved by water quenching from the austenitic phase This structure com bines m echanical with m agnetic hardness I n addition to carbon, alloying elem ents such as cobalt or chrom ium are present 5.4.3 Basis of subclassification The recommended subclassification is based on the cobalt content 5.4.4 Available forms These m aterials are available as hot-rolled sections 5.4.5 Physical characteristics A m ore complete definition of these materials may be based on the following characteristics: • • • • • m agnetic: therm al: m echanical: m etallurgical state: dim ensions: maxim um BH product, rem anent flux density, coercivity; tem perature coefficients of magnetic remanence and of coercivity, and Curie temperature; density; hot-rolled and quenched, tem pered; determ ined by application For h ysteresis m otors which are the m ain application of these m aterials, a tempering heat treatm ent in the range 300 °C to 550 °C is applied This reduces the coercivity HcB and im proves the fullness of the curve I EC 60404-1 : 201 © I EC 201 – 41 – This application requires m aterial in the form of a thin walled cylinder, mechanicall y strong and magneticall y homogeneous 5.4.6 Main applications In the tem pered condition the materials are used for h ysteresis m otors Their use in other conditions is almost obsolete 5.5 Class U – Bonded magnetically hard materials 5.5.1 General These bonded m agnets are com posite m aterials They consist of permanent magnet powders em bedded in a plastic matrix This binder phase determ ines to a large extent the mechanical properties of the composite, while the m agnet powder determines its magnetic properties The properties of the composite are determ ined not onl y by the type of magnet powder and the matrix m aterial but also by the fill factor and for anisotropic m aterial the degree of alignment There is a wide variety of grades In spite of their lower magnetic values compared with sintered materials, bonded magnets offer economic and technical advantages in m an y applications because they are cost-effective to manufacture and allow a wide scope for shaping and good mechanical properties Expensive and elaborate processing steps required in powder m etallurgy are not needed 5.5.2 5.5.2.1 Class U1 – Bonded aluminium-nickel-cobalt-iron-titanium (AlNiCo) magnets Reference document These m aterials are covered by I EC 60404-8-1 5.5.2.2 Chemical composition and manufacturing method These bonded m agnets contain crushed alloys as given in class R1 together with a resin binder This m ixture is pressed at elevated tem perature and cured 5.5.2.3 Basis of subclassification The recommended subclassification is based on the chemical composition, the degree of magnetic anisotropy and the m anufacturing m ethod 5.5.2.4 Available form The magnets are mainl y produced in the form of sm all blocks 5.5.2.5 Physical characteristics The m agnetic properties are determined by the alloy and the fill factor of the bond ing material The thermal properties are determ ined by the alloy and the bonding material Ranges of specified values of magnetic properties and density for isotropic bonded AlN iCo magnets are given in the corresponding product specification 5.5.2.6 Main applications The m aterials are used for watt-hour meters and measuring devices – 42 – 5.5.3 5.5.3.1 I EC 60404-1 : 201 © I EC 201 Class U – Bonded rare earth-cobalt (RECo) magnets Reference document These m aterials are covered by I EC 60404-8-1 5.5.3.2 Chemical composition and manufactu ring method These bonded magnets contain powdered alloys as given in class R5 The powder is mixed with a suitable binder and the compact is then formed to shape using either compression or injection moulding 5.5.3.3 Basis of su bclassification The recomm ended subclassification is based on the chem ical com position, the degree of magnetic anisotropy and the manufacturing method 5.5.3.4 Available forms The magnets are produced in simple shapes by com pression m oulding More com plicated shapes are produced by injection moulding 5.5.3.5 Physical characteristics The magnetic properties are determ ined by the alloy and the fill factor of the bonding material The m agnets m ay be isotropic or by the application of a m agnetic field, anisotropic magnets may be produced The thermal properties are determined by the alloy and the bonding m aterial Ranges of specified values of magnetic properties and density for isotropic and anisotropic bonded RECo magnets are given in the corresponding product specification 5.5.3.6 M ain applications The m aterials are used in small motors, follower drives, HiFi equipm ent, sensors and watches 5.5.4 5.5.4.1 Class U – Bonded neodymiu m-iron-boron (REFeB) magnets Reference document These m aterials are covered by I EC 60404-8-1 5.5.4.2 Chemical composition and manufacturing method These bonded m agnets contain powdered alloys as given in class R7 The powder is mixed with a suitable binder and the compact is then formed to shape using either compression or injection m oulding 5.5.4.3 Basis of subclassification The recommended subclassification is based on the chemical com position, the degree of magnetic anisotropy and the m anufacturing m ethod 5.5.4.4 Available forms The magnets are produced in sim ple shapes by compression moulding More complicated shapes are produced by injection m oulding I EC 60404-1 : 201 © I EC 201 5.5.4.5 – 43 – Physical characteristics The m agnetic properties are determined by the alloy and the fill factor of the bond ing material The m agnets may be isotropic or, by the application of a magnetic field, anisotropic m agnets may be produced The therm al properties are determined by the alloy and the bonding material Ranges of specified values of m agnetic properties and density for isotropic bonded N dFeB magnets are given in the corresponding product specification 5.5.4.6 Main applications The m aterials are used in sm all motors, hand tools, follower drives, sensors and H iFi equipm ent 5.5.5 5.5.5.1 Class U4 – Bonded hard ferrite magnets Reference document These m aterials are covered by I EC 60404-8-1 5.5.5.2 Chemical composition and manufacturing method These bonded magnets contain powdered ferrites as given in class S1 The powder is mixed with a suitable binder and the com pact is then form ed into shape This can be by com pression, injection m oulding, extrusion or by rolling 5.5.5.3 Basis of subclassification The recommended subclassification is based on the chem ical composition, the degree of magnetic anisotropy and the manufacturing m ethod 5.5.5.4 Available forms The m agnets are produced in sim ple shapes by compression m oulding or extrusion Sheets of magnet m aterial can be produced by rolling More complicated shapes are produced by injection moulding 5.5.5.5 Physical characteristics The m agnetic properties are determ ined by the ferrite a and the fill factor of the bond ing material The magnets m ay be isotropic Anisotropic magnets m ay be produced by com pression m oulding or rolling or by the application on a m agnetic field The therm al properties are determined by the alloy and the bonding m aterial Ranges of specified values of magnetic properties and density for isotropic and anisotropic bonded hard ferrite magnets are given in the corresponding product specification 5.5.5.6 Main applications The m aterials are used in magnetic catches, holding m agnets, magnetic displays, sm all motors and toys – 44 – 5.5.6 5.5.6.1 I EC 60404-1 : 201 © I EC 201 Class U5 – Bonded rare earth-iron-nitrogen magnets Reference document These m aterials are covered by I EC 60404-8-1 5.5.6.2 Chemical composition and manufacturing method These bonded m agnets contain powdered Sm Fe N interm etallic com pound These materials consist of 22 % to 27 % sam arium , 3, % to 4,0 % nitrogen and the balance iron The Sm FeN powders are m anufactured by the reduction diffusion process using Sm O and Fe powders with calcium as a reductant followed by nitrogenation When the size of the processed powders is coarse, a subsequent m illing is required The powder is m ixed with a suitable binder and the compact is then form ed to shape using inj ection m oulding in a m agnetic field Obtained bonded magnets are usuall y anisotropic 5.5.6.3 Basis of subclassification The recommended subclassification is based on the chem ical com position 5.5.6.4 Available forms The m agnets are produced in sim ple shape by injection m oulding in a magnetic field 5.5.6.5 Physical characteristics The magnetic properties are determ ined by the alloy, the fill factor of the bond ing m aterial and the m agnetic field strength for alignment The therm al properties are determined by the alloy and the bonding m aterial Ranges of specified values of m agnetic properties and density for anisotropic bonded REFeN magnets are given in the corresponding product specification 5.5.6.6 Main applications The materials are used in sm all motors such as stepping and spindle m otors and sensors _ I N TE RN ATI O N AL E LE CTRO TE CH N I CAL CO M M I S S I O N 3, ru e d e Va re m bé P O B ox CH -1 1 G e n e va S wi tze rl a n d Te l : + 41 F a x: + 22 91 02 1 22 91 03 00 i n fo @i e c ch www i e c ch