1、Designation: A1101 16Standard Specification forSintered and Fully Dense Neodymium Iron Boron (NdFeB)Permanent Magnets1This standard is issued under the fixed designation A1101; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses 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 and fully d
3、enseneodymium iron boron (Nd2Fe14B, NdFeB, or “Neo”) perma-nent magnets. These materials are available in a wide range ofcompositions with a commensurately large range of magneticproperties. The numbers in the Nd2Fe14B name indicate theapproximate atomic ratio of the key elements.1.2 Neodymium iron
4、boron magnets have approximatemagnetic properties of residual magnetic induction, Br, from1.08 T (10 800 G) up to 1.5 T (15 000 G) and intrinsic coercivefield strength, HcJ, of 875 kA/m (11 000 Oe) to above 2785kA/m (35 000 Oe). Special grades and isotropic (un-aligned)magnets can have properties ou
5、tside these ranges (see Appen-dix X4). Specific magnetic hysteresis behavior (demagnetiza-tion curve) can be characterized using Test Method A977/A977M.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to customary (cgs-emu a
6、nd 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 with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practi
7、ces 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 TestingA977/A977M Test Method for Magnetic Properties of High-Coercivity Permanent Magnet Materials Using Hyster-esig
8、raphs2.2 Other Standards:MMPA Standard No. 0100-00 Standard Specifications forPermanent Magnet Materials3IEC 60404-8-1 Magnetic Materials Part 8: Specifications forIndividual Materials Section 1 Standard Specificationsfor Magnetically Hard Materials43. Terminology3.1 The terms and symbols used in th
9、is specification, unlessotherwise noted, are defined 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 permeability corre-sponding to the slope of the recoil line. For reference seeinc
10、remental, 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 permeability is dimension-less. Note that in producers product literature recoil
11、 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-sidual induction, Br, and intrinsic coercive field strength, HcJ.The cha
12、nge in these characteristics over a defined and limitedtemperature range can be reversible, that is, nondestructive.This change is represented by values called reversible tempera-ture coefficients. The symbol for reversible temperature coef-ficient of induction is (Br) and of (intrinsic) coercivity
13、is(HcJ). They are expressed in percent change per degreeCelsius, %/C, or the numerically equivalent percent perKelvin, %/K, and represent the average rate of change of the1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Sub
14、committee A06.02 onMaterial Specifications.Current edition approved Nov. 1, 2016. Published November 2016. DOI:10.1520/A1101162For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
15、 refer to the standards Document Summary page onthe ASTM website.3Available from the Permanent Magnet Division of the SMMA (www.sm-ma.org). It was previously available from The International Magnetics Association(IMA). The IMA had been the successor to the MMPA and both organizations(MMPA and IMA) n
16、o longer exist.4Available from International Electrotechnical Commission (IEC), 3, rue deVaremb, 1st Floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, http:/www.iec.ch.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1characteristic
17、 within the specified temperature range. Thechange in magnetic characteristics is nonlinear, so it is neces-sary to specify the temperature range over which the coefficientapplies.3.2.3 The maximum recommended working temperature ofa permanent magnet, Tw, is a semi-arbitrary value sometimesassigned
18、by magnet manufacturers to their products. Twis notnormative. See Appendix X6 for a more complete discussion.4. Classification4.1 The classification of neodymium iron boron permanentmagnets is given in Table 1. Cross-reference to MMPAstandard No. 0100-00 and IEC 60404-8-1 is provided inAppendix X1.5
19、. Ordering Information5.1 Orders for parts conforming to this specification shallinclude the following information:5.1.1 Reference to this specification 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 m
20、inimum values listed in the tables.5.1.4 Quantity required.5.1.5 The required magnetization state of the providedmaterial (unmagnetized, fully magnetized, magnetized andthermally stabilized, magnetized and then partially demagne-tized). This information should appear on the part drawingwhenever poss
21、ible.5.1.6 Certification of magnetic property evaluation.5.1.7 Marking and packaging requirements.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 Neodymium iron
22、boron magnets should be specifiedprimarily by magnetic performance. Chemical composition canhave an influence on both magnetic and physical characteristicsbut should only be specified when other options are insufficientto meet user requirements. Agreement on composition must bemutually arrived at by
23、 producer and user.6.2 The general chemical composition of neodymium ironboron includes the elements neodymium, iron, and boron.Approximate chemical compositions are listed in Table X3.1and are typical but not mandatory.6.3 There are a number of additional elements included inthe alloy to adjust mag
24、netic, chemical, or mechanical proper-ties. See Appendix X3 for additional information.7. Physical and Mechanical Properties7.1 Typical thermal and physical properties are listed inTable X2.1 in Appendix X2.7.2 Physical density values are given for information pur-poses only and are not mandatory.7.
25、3 Neodymium iron boron magnets are used for theirmagnetic characteristics. The end-use application should notrely on them for structural purposes due to low tensile andflexural strength. These materials are brittle, and can chip orbreak easily. Magnetic properties may also be affected byphysical str
26、ess.7.4 Strength testing of brittle materials such as neodymiumiron boron is difficult, expensive, time-consuming, and theremay be considerable scatter in the measured values. Producerstypically make a complete set of measurements at the onset ofproduction and they are seldom repeated.8. Magnetic Pr
27、operty Requirements8.1 Magnetic properties are listed in Table 1.8.2 The values of magnetic properties listed in the table arespecified minimum values at 20 6 2C(686 4 F),determined after magnetizing to saturation in closed magneticcircuit.8.3 The specified values of magnetic properties are validonl
28、y 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 nature of permanent magnet production,magnetic testing of each lot is recommended,
29、 especially forapplications where the magnet performance is closely speci-fied. Such magnetic property evaluations shall be conducted inthe manner described below. Where the magnet shape is notsuitable for magnetic testing, a specimen shall be cut from themagnet using appropriate slicing and grindin
30、g 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 A977/A977M, or by using a suitable,mutually agreed upon magnetometric method.8.4.2 When magnets are being purchased in the fullymagnetized con
31、dition, the testing shall determine the magneticproperties from the as-received magnetization state, followedby magnetization to saturation and testing of the magneticproperties from the fully magnetized condition.8.4.3 When magnets are being purchased in the unmagne-tized condition or in an unknown
32、 state of magnetization, thetest laboratory shall magnetize the test specimen(s) to satura-tion in the same orientation as the received specimens indi-cated direction of magnetization and measure the magneticproperties from this fully magnetized condition.8.4.4 When magnets are being purchased in a
33、calibrated,stabilized, or “knocked-down” condition, magnets should behandled with care to prevent exposure to externally appliedfields. Refer to Appendix X6 for an explanation of these terms.During testing using Test Method A977/A977M, the measure-ment should proceed in the second quadrant only, wit
34、houtattempting to saturate the magnet specimen, to avoid changingthe magnetization state of the material prior to test.8.4.5 Other test methods may be utilized as agreed tobetween producer and user. Such tests may include the opencircuit magnetization Helmholtz test, field strength measure-ments in
35、a defined magnetic circuit or adjacent to the magnetsurface.A1101 162TABLE 1 Neodymium Iron Boron Permanent Magnets: Classification and Minimum Magnetic PropertyARequirementsASTM DesignationBMaximumEnergy Product(BH)maxResidualInductionBrCoercive FieldStrengthHcBIntrinsic CoerciveField StrengthHcJkJ
36、/m3(MGOe) mT (G) kA/m (Oe) kA/m (Oe)ANISOTROPIC Nd2Fe14BND-SA-333/875 333 (41.8) 1325 (13250) 832 (10450) 875 (11000)ND-SA-355/875 355 (44.6) 1369 (13690) 832 (10450) 875 (11000)ND-SA-370/875 370 (46.5) 1397 (13970) 832 (10450) 875 (11000)ND-SA-385/875 385 (48.4) 1426 (14260) 832 (10450) 875 (11000)
37、ND-SA-407/875 407 (51.1) 1465 (14650) 832 (10450) 875 (11000)ND-SA-222/955 222 (27.9) 1082 (10820) 820 (10300) 955 (12000)ND-SA-244/955 244 (30.7) 1136 (11360) 861 (10820) 955 (12000)ND-SA-259/955 259 (32.5) 1168 (11680) 907 (11400) 955 (12000)ND-SA-281/955 281 (35.3) 1218 (12180) 907 (11400) 955 (1
38、2000)ND-SA-296/955 296 (37.2) 1250 (12500) 907 (11400) 955 (12000)ND-SA-311/955 311 (39.1) 1281 (12810) 907 (11400) 955 (12000)ND-SA-333/955 333 (41.8) 1325 (13250) 907 (11400) 955 (12000)ND-SA-355/955 355 (44.6) 1369 (13690) 907 (11400) 955 (12000)ND-SA-370/955 370 (46.5) 1397 (13970) 907 (11400) 9
39、55 (12000)ND-SA-385/955 385 (48.4) 1426 (14260) 907 (11400) 955 (12000)ND-SA-222/1114 222 (27.9) 1082 (10820) 820 (10300) 1114 (14000)ND-SA-244/1114 244 (30.7) 1136 (11360) 861 (10820) 1114 (14000)ND-SA-259/1114 259 (32.5) 1168 (11680) 885 (11120) 1114 (14000)ND-SA-281/1114 281 (35.3) 1218 (12180) 9
40、23 (11600) 1114 (14000)ND-SA-296/1114 296 (37.2) 1250 (12500) 947 (11900) 1114 (14000)ND-SA-311/1114 311 (39.1) 1281 (12810) 971 (12200) 1114 (14000)ND-SA-333/1114 333 (41.8) 1325 (13250) 1004 (12620) 1114 (14000)ND-SA-355/1114 355 (44.6) 1369 (13690) 1058 (13300) 1114 (14000)ND-SA-370/1114 370 (46.
41、5) 1397 (13970) 1058 (13300) 1114 (14000)ND-SA-385/1114 385 (48.4) 1426 (14260) 1058 (13300) 1114 (14000)ND-SA-207/1353 207 (26.0) 1045 (10450) 792 (9950) 1353 (17000)ND-SA-222/1353 222 (27.9) 1082 (10820) 820 (10300) 1353 (17000)ND-SA-244/1353 244 (30.7) 1136 (11360) 861 (10820) 1353 (17000)ND-SA-2
42、59/1353 259 (32.5) 1168 (11680) 885 (11120) 1353 (17000)ND-SA-281/1353 281 (35.3) 1218 (12180) 923 (11600) 1353 (17000)ND-SA-296/1353 296 (37.2) 1250 (12500) 947 (11900) 1353 (17000)ND-SA-311/1353 311 (39.1) 1281 (12810) 971 (12200) 1353 (17000)ND-SA-333/1353 333 (41.8) 1325 (13250) 1004 (12620) 135
43、3 (17000)ND-SA-355/1353 355 (44.6) 1369 (13690) 1038 (13040) 1353 (17000)ND-SA-370/1353 370 (46.5) 1397 (13970) 1058 (13300) 1353 (17000)ND-SA-207/1592 207 (26.0) 1045 (10450) 792 (9950) 1592 (20000)ND-SA-222/1592 222 (27.9) 1082 (10820) 820 (10300) 1592 (20000)ND-SA-244/1592 244 (30.7) 1136 (11360)
44、 861 (10820) 1592 (20000)ND-SA-259/1592 259 (32.5) 1168 (11680) 885 (11120) 1592 (20000)ND-SA-281/1592 281 (35.3) 1218 (12180) 923 (11600) 1592 (20000)ND-SA-296/1592 296 (37.2) 1250 (12500) 947 (11900) 1592 (20000)ND-SA-311/1592 311 (39.1) 1281 (12810) 971 (12200) 1592 (20000)ND-SA-333/1592 333 (41.
45、8) 1325 (13250) 1004 (12620) 1592 (20000)ND-SA-355/1592 355 (44.6) 1369 (13690) 1038 (13040) 1592 (20000)ND-SA-207/1989 207 (26.0) 1045 (10450) 792 (9950) 1989 (25000)ND-SA-222/1989 222 (27.9) 1082 (10820) 820 (10300) 1989 (25000)ND-SA-244/1989 244 (30.7) 1136 (11360) 861 (10820) 1989 (25000)ND-SA-2
46、59/1989 259 (32.5) 1168 (11680) 885 (11120) 1989 (25000)ND-SA-281/1989 281 (35.3) 1218 (12180) 923 (11600) 1989 (25000)ND-SA-296/1989 296 (37.2) 1250 (12500) 947 (11900) 1989 (25000)ND-SA-311/1989 311 (39.1) 1281 (12810) 971 (12200) 1989 (25000)ND-SA-333/1989 333 (41.8) 1325 (13250) 1004 (12620) 198
47、9 (25000)ND-SA-207/2387 207 (26.0) 1045 (10450) 792 (9950) 2387 (30000)ND-SA-222/2387 222 (27.9) 1082 (10820) 820 (10300) 2387 (30000)ND-SA-244/2387 244 (30.7) 1136 (11360) 861 (10820) 2387 (30000)ND-SA-259/2387 259 (32.5) 1168 (11680) 885 (11120) 2387 (30000)ND-SA-281/2387 281 (35.3) 1218 (12180) 9
48、23 (11600) 2387 (30000)ND-SA-207/2785 207 (26.0) 1045 (10450) 792 (9950) 2785 (35000)ND-SA-222/2785 222 (27.9) 1082 (10820) 820 (10300) 2785 (35000)ND-SA-244/2785 244 (30.7) 1136 (11360) 861 (10820) 2785 (35000)AMagnetic properties at 20 C (68 F).BThe ASTM designation conforms to the requirements of
49、 this specification. ASTM Designations are of the form MM-TT-XX/YY where:MM = material (ND = neodymium iron boron),TT = type of processing and orientation (S = sintered; I = isotropic (non-oriented), A = anisotropic (oriented),XX = energy product in kJ/m3rounded to the nearest integer, andYY = intrinsic coercivity in kA/m rounded to the nearest integer.A1101 1639. Workmanship, Finish, and Appearance9.1 Dimensions and tolerances shall be as specified on themagnet drawing and must be agreed upon between the pro-ducer and the user.9.2 Though porosity and voids are unco
