1、Designation:A105416Standard Specification forSintered Ferrite Permanent Magnets1This standard is issued under the fixed designation A1054;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parenthes
2、es indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers technically important,com-mercially available,magnetically hard sintered ferrite perma-nent magnets.1.2 Ferrite permanent magnets ha
3、ve residual induction Brfrom 0.2 T(2000 G)up to about 0.5 T(5000 G)and intrinsiccoercive field strength HcJfrom 160 kA m(2000 Oe)up toabout 400 kA/m(5000 Oe).Their specific magnetic hysteresisbehavior(demagnetization curve)can be characterized usingTest Method A977/A977M.1.3 The values stated in SI
4、units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to customary(cgs-emu and inch-pound)unitswhich are provided for information only and are not consideredstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated wi
5、th its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A340 Terminology of Symbols and Definitions Relating toMagnetic Test
6、ingA977/A977M Test Method for Magnetic Properties of High-Coercivity Permanent Magnet Materials Using Hyster-esigraphs2.2 Other Standards:MMPA Standard No.0100-00 Standard Specifications forPermanent Magnet Materials3IEC 60404-8-1 Magnetic Materials Part 8:Specifications forindividual materials Sect
7、ion 1 Standard specificationsfor magnetically hard materials43.Terminology3.1 The terms and symbols used in this specification aredefined in Terminology A340.3.2 Terms that are not defined in Terminology A340 but arein common usage and used herein are as follows.3.2.1 Recoil permeability,REC,is the
8、permeability corre-sponding to the slope of the recoil line.For reference,seeincremental,relative,and reversible permeabilities as definedin Terminology A340.In practical use,this is the slope of thenormal hysteresis loop in the second quadrant and in proximityto the B-axis.The value of recoil perme
9、ability is dimension-less.Note that in producers product literature,recoil perme-ability is sometimes represented by the symbol r,which isdefined by Terminology A340 as relative permeability.3.2.2 Magnetic characteristics change with temperature.Two key metrics of permanent magnet performance are re
10、-sidual induction,Br,and intrinsic coercive field strength,HcJ.The change in these characteristics over a defined and limitedtemperature range can be reversible,that is,non-destructive.This change is represented by values called reversible tempera-ture coefficients.The symbol for reversible temperat
11、ure coef-ficient of induction is(Br)and of(intrinsic)coercivity is(HcJ).They are expressed in percent change per degreeCelsius,%/C,or the numerically equivalent percent perKelvin,%/K.The change in magnetic characteristics is non-linear so it is necessary to specify the temperature range overwhich th
12、e coefficient applies.3.2.3 The maximum recommended working temperature ofa permanent magnet,Tw,is a semi-arbitrary value sometimesassigned by magnet manufacturers to their products.Twis notnormative.See Appendix X3 for a more complete discussion.4.Classification4.1 The classification of ferrite per
13、manent magnets is givenin Tables 1 and 2,with cross-reference to MMPAStandard No.0100-00 and IEC 60404-8-1 standards.1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.02 onMaterial Specifications.Current edi
14、tion approved Nov.1,2016.Published November 2016.Originallyapproved in 2007.Last previous addition approved in 2014 as A1054 14.DOI:10.1520/A1054-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards
15、volume information,refer to the standards Document Summary page onthe ASTM website.3Available from The International Magnetics Association(IMA),8 SouthMichigan Avenue,Suite 1000,Chicago,IL 60603.4Available from IEC(International Electrotechnical Commission)Central Office3,rue de Varemb,P.O.Box 131,C
16、H-1211,GENEVA 20 Switzerland.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Ordering Information5.1 Orders for parts conforming to this specification shallinclude the following information:5.1.1 Reference to this standard and year of issue/revision.5.1.2 Reference to an applicable part drawing.5.1.3 Magnetic property requirements if they are morestringent than the minimum values listed in the tables.5.1.4 Quantity required.5.1.5 Th
