1、Designation: A 1054 07Standard Specification forSintered Ceramic Ferrite Permanent Magnets1This standard is issued under the fixed designation A 1054; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers technically important, com-mercially available, magnetically hard sintered ceramic ferritepermanent magnets.1.2
3、 Ceramic ferrite magnets have residual magnetic induc-tion Br from 2000 G (0.2 T) up to about 5000 G (0.5 T) andintrinsic coercive field strength Hci(HcJ) from 2000 Oe(160 kA/m) up to about 5000 Oe (400 kA/m). Their specificmagnetic hysteresis behavior (demagnetization curve) can becharacterized usi
4、ng Test Method A 977/A 977M.1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values givenin parentheses are mathematical conversions to SI units whichare provided for information only and are not consideredstandard.1.4 This standard does not purpo
5、rt to address all of thesafety concerns, if any, associated with 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:2A 34
6、0 Terminology of Symbols and Definitions Relating toMagnetic TestingA 977/A 977M Test Method for Magnetic Properties ofHigh-Coercivity Permanent Magnet Materials Using Hys-teresigraphs2.2 Other Standards:MMPA Standard No. 0100-00 Standard Specifications forPermanent Magnet Materials3IEC60404-8-1 Mag
7、netic Materials Part 8: Specifications forindividual materials Section 1 Standard specificationsfor magnetically hard materials4International Air Transport Association (IATA) DangerousGoods Regulations, Packing Instruction 90253. Terminology3.1 The terms and symbols used in this specification aredef
8、ined in Terminology A 340.4. Classification4.1 The classification of ceramic ferrite permanent magnetsis given in Tables 1 and 2, with cross-reference to MMPAStandard No. 0100-00 and IEC60404-8-1 standards.5. Ordering Information5.1 Orders for parts conforming to this specification shallinclude the
9、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 that the minimum values listed in the tables.5.1.4 Quantity required.5.1.5 The required magnetization state o
10、f the providedmaterial (unmagnetized, fully magnetized, magnetized andthermally stabilized, magnetized and partially demagnetized or“calibrated”). This information should appear on the partdrawing whenever possible.5.1.6 Certification of magnetic property evaluation.5.1.7 Marking and packaging requi
11、rements.5.1.8 Exceptions to this specification or special require-ments such as plating, coating, or functional testing as mutuallyagreed upon by the producer and user.6. Chemical Composition6.1 The general chemical composition of ceramic ferritemagnets is MO 6Fe2O3with M being barium, strontium, or
12、some combination of the two. New ferrite grades may also1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.02 onMaterial Specifications.Current edition approved May 1, 2007. Published June 2007.2For reference
13、d ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from The International Magnetics Association (IMA), 8 SouthMichi
14、gan Avenue, Suite 1000, Chicago, IL 60603.4Available from IEC (International Electrotechnical Commission) Central Office3, rue de Varemb, P.O. Box 131, CH - 1211, GENEVA 20 Switzerland.5Available from IATA, 800 Place Victoria, PO Box 113, Montral, Quebec, H4Z1M1.1Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.include some rare earth elements. Chemical compositionslisted in the tables are typical and are not guaranteed.7. Physical and Mechanical Properties7.1 Typical thermal properties are listed in Appendix X1.7.2 Typical physi
16、cal properties are listed in Appendix X2.7.3 Physical density values are given for information pur-poses only and are not guaranteed.7.4 Ceramic magnets are used for their magnetic character-istics. The end-use application should not rely on them forstructural purposes due to low tensile and flexura
17、l strength.These materials are very brittle, and they chip and break easily.8. Magnetic Property Requirements8.1 Magnetic properties are listed in Tables 1 and 2.8.2 The values of essential magnetic properties listed in thetable are specified minimum values at +68F (+20C), deter-mined after magnetiz
18、ing to full saturation.8.3 The specified values of magnetic properties are validonly for magnet test specimens with a uniform cross-sectionalong the axis of magnetization. Properties for anisotropic(magnetically oriented) magnets are measured along the axis ofpreferred orientation.8.4 Because of the
19、 nature of permanent magnet production,magnetic testing of each lot is strongly recommended, espe-cially for applications where the magnet performance is closelyspecified. Such magnetic property evaluations shall be con-ducted in the manner described below. Where the magnet shapeis not suitable for
20、magnetic testing, a sample shall be cut fromthe magnet using appropriate slicing and grinding techniques,paying attention to any magnetic orientation within the magnet.8.4.1 The magnetic properties shall be determined in accor-dance with Test Method A 977/A 977M, or by using a suitable,mutually agre
21、ed upon magnetometer.8.4.2 When magnets are being purchased in the fullymagnetized condition, the testing shall determine the magneticproperties from the as-received magnetization state, followedby magnetization to full saturation and testing of the magneticproperties from the fully magnetized condi
22、tion.TABLE 1 Classification and Minimum Magnetic Property Requirements for Isotropic Sintered Ceramic Ferrite MagnetsMaterial Magnetic PropertiesASTMDesignationAMMPABriefDesignationOriginalMMPAClassIECBriefDesignationIECCodeReferenceMaximumEnergyProduct,MGOe(kJ/m3)RemanentInductionBr,gauss (mT)Norma
23、lCoerciveField Strength,Hc (HcB)oersted (kA/m)IntrinsicCoerciveField Strength,Hci(HcJ)oersted (kA/m)RelativeRecoilPermeability,rec G/OeCE-I-01 . . . S1-0-1 1.05 (8.4) 2300 (230) 1860 (148) 3250 (259) 1.2ADesignations are XX-Y-ZZZ where:XX = material type (CE = ceramic ferrite),Y = processing and ori
24、entation (I = isotropic (non-oriented), A = anistropic (oriented), andZZZ = numeric grade designation.TABLE 2 Classification and Minimum Magnetic Property Requirements for Anisotropic Sintered Ceramic Ferrite MagnetsMaterial Magnetic PropertiesASTMDesignationAMMPABriefDesignationOriginalMMPAClassIEC
25、BriefDesignationIECCodeReferenceMaximumEnergyProduct,MGOe(kJ/m3)RemanentInductionBr,gauss (mT)NormalCoerciveField Strength,Hc (HcB)oersted (kA/m)IntrinsicCoerciveField Strength,Hci(HcJ)oersted (kA/m)RelativeRecoilPermeabilityrec G/OeCE-A-02 . Ceramic 2 . . 1.8 (14.3) 2900 (290) 2400 (191) 3000 (239)
26、 1.1CE-A-05 3.4/2.5 Ceramic 5 Hard ferrite 26/18 S1-1-6 3.40 (27.1) 3800 (380) 2400 (191) 2500 (199) 1.1CE-A-06 . Ceramic 6 . . 2.45 (19.5) 3200 (320) 2820 (225) 3300 (263) 1.1CE-A-07 2.7/4.0 Ceramic 7 Hard ferrite 20/28 S1-1-2 2.75 (21.9) 3400 (340) 3250 (259) 4000 (318) 1.1CE-A-08A 3.5/3.1 Ceramic
27、 8A Hard ferrite 25/12 S1-1-5 3.50 (27.9) 3850 (385) 2950 (235) 3050 (243) 1.1CE-A-08B . Ceramic 8B . . 4.12 (32.8) 4200 (420) 2913 (232) 2960 (236) 1.1CE-A-10 . Ceramic 10 . . 3.82 (30.4) 4000 (400) 3617 (288) 3510 (280) 1.1CE-A-11 . Ceramic 11 . . 4.32 (34.4) 4300 (430) 2512 (200) 2560 (204) 1.1CE
28、-A-21 3.4/3.9 . . . 3.40 (27.1) 3800 (380) 3400 (271) 3900 (310) 1.1CE-A-22 4.0/2.9 . . . 4.00 (31.8) 4100 (410) 2800 (223) 2900 (231) 1.1CE-A-23 3.2/4.8 . . . 3.20 (25.5) 3700 (370) 3500 (279) 4800 (382) 1.1CE-A-24 3.8/4.0 . . . 3.80 (30.3) 4000 (400) 3560 (283) 4000 (318) 1.1ADesignations are XX-Y
29、-ZZZ where:XX = material type (CE = ceramic ferrite),Y = processing and orientation (I = isotropic (non-oriented), A = anistropic (oriented), andZZZ = numeric grade designation.A10540728.4.3 When magnets are being purchased in the unmagne-tized condition or in an unknown state of magnetization, thet
30、est laboratory shall magnetize the test sample(s) to fullsaturation and measure the magnetic properties from the fullymagnetized condition.8.4.4 When the magnets are being purchased in a calibrated,stabilized, or “knocked-down” condition, testing should beperformed by a method other than Test Method
31、 A 977/A 977Mto avoid changing the magnetization state of the material. AHelmholtz coil set and fluxmeter are often used to check theopen-circuit magnetization of magnets without changing themagnetization state; this is a one-point test which does not fullycharacterize the magnetic properties but ma
32、y be a suitablescreening tool in production.9. Workmanship, Finish and Appearance9.1 Dimensions and tolerances shall be as specified on themagnet drawing and must be agreed upon between the user andthe producer.9.2 Cracks, porosity, and voids are common in sinteredferrite magnets and shall not in th
33、emselves constitute reasonfor rejection unless agreed upon between user and producer.Allowable defects shall be documented in writing as part of theordering or contracting process.9.3 Magnets shall be free of loose chips and surface residuewhich may interfere with assembly or proper device function.
34、9.4 Chips shall be acceptable if no more than 5 % of anysurface identified as a magnetic pole surface is removed.9.5 Cracks shall be acceptable provided they do not extendacross more than 50 % of any surface identified as a magneticpole surface.10. Sampling10.1 A lot shall consist of parts of the sa
35、me form anddimensions, produced from a single mixed powder batch orsintering run, or both, from an unchanged process, withoutdiscontinuity in production, and submitted for inspection at onetime.10.2 The user and producer shall agree upon a representa-tive number of specimens for testing. Typically,
36、a suitablenumber of parts, as mutually agreed upon between producerand user, shall be randomly selected from each lot. It isadvisable to test a minimum of two parts from each lot, andmore if there is reason to suspect that the magnetic propertiesare not uniform throughout the lot.11. Rejection and R
37、ehearing11.1 Parts that fail to conform to the requirements of thisspecification shall be rejected. Rejection should be reported tothe producer or supplier promptly and in writing. In case ofdissatisfaction with the results of the test, the producer maymake claim for a rehearing.11.2 The disposition
38、 of rejected parts shall be subject toagreement between the user and the producer.12. Certification12.1 When specified in the purchase order or contract, theuser shall be furnished certification that samples representingeach lot have been either tested or inspected as directed in thisspecification a
39、nd that the requirements have been met.12.2 When specified in the purchase order or contract, areport of the test results shall include:12.2.1 Grade of material.12.2.2 Magnetic test results.12.2.3 The results of any other tests stipulated in thepurchase order or contract.13. Packaging and Package Ma
40、rking13.1 Packaging shall be subject to agreement between theuser and the producer.13.2 Parts furnished under this specification shall be in acontainer identified by the name or symbol of the partsproducer.13.3 Magnetized parts shall be properly labeled as such forsafe handling and shipping purposes
41、.13.3.1 Unless declared as “Dangerous Goods,” magnetizedparts to be shipped via aircraft must be packaged in anappropriate manner so the closed shipping container meets theIATA magnetic requirements for air shipment. This mayrequire 1) rearranging the parts within the shipping container,or 2) adding
42、 sheets of steel or other magnetically soft shieldingmaterial, or both, to reduce the magnetic field external to theshipping container below the required levels.14. Keywords14.1 ceramic ferrite; ceramic magnet; coercive fieldstrength; ferrite magnet; hard ferrite; magnetic induction;magnetic propert
43、ies; permanent magnet; sintered ceramic fer-rite; sintered ferrite magnetA1054073APPENDIXES(Nonmandatory Information)X1. TYPICAL THERMAL PROPERTIES OF CERAMIC MAGNETSReversible temperature coefficient of residual induction -0.2 %/CReversible temperature coefficient of intrinsic coercive field streng
44、th +0.2 to +0.5 %/CCurie temperature 450CMaximum exposure temperature without structural change 800CX2. TYPICAL PHYSICAL PROPERTIES OF CERAMIC MAGNETSDensity 4.9 to 5.1 g/cm3(4.9 to 5.1 3 103kg/m3)Coefficient of thermal expansionPerpendicular to magnetic orientation 10 ppm/CParallel to magnetic orie
45、ntation 14 ppm/CThermal conductivity 0.007 cal/cm-secC (2.93 J/m-secC)Electrical resistivity 106ohm-cm (104ohm-m)Porosity 5 %Modulus of elasticity 2.5 3 107psi (170 3109Pa)Poisson ratio 0.28Compressive strength 130 000 psi (900 3 106Pa)Tensile strength 5000 psi (35 3 106Pa)Flexural strength 9000 psi
46、 (62 3 106Pa)Hardness 7 MohsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infr
47、ingement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standa
48、rd or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your vie
49、ws known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A1054074
