1、Designation: A1102 16Standard Specification forSintered Samarium Cobalt (SmCo) Permanent Magnets1This standard is issued under the fixed designation A1102; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 (fully dense)permanent magnets c
3、ommonly known as samarium cobalt.These materials are available in two general compositionfamilies abbreviated “SmCo 1:5” and “SmCo 2:17.” Thenumbers indicate the approximate atomic ratio of samarium tothe sum of other constituents. (Refer to Appendix X3 foradditional composition information.)1.2 Sam
4、arium cobalt magnets have approximate magneticproperties of residual magnetic induction, Br, from 0.78 T(7800 G) to 1.18 T (11 800 G) and intrinsic coercivity, HcJ,typically greater than 800 kA/m (10 000 Oe). Special gradesand isotropic (un-aligned) magnets can have properties outsidethese ranges (s
5、ee Appendix X4). Specific magnetic hysteresisbehavior (demagnetization curve) can be characterized usingTest 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 and inch-pound) unitswhich
6、 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 practices and determine the app
7、lica-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-esigraphs2.2 Other Standards:
8、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 this specification, unlesso
9、therwise 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 seeincremental, relative, and r
10、eversible 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 perme-ability is sometim
11、es 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 change in these characterist
12、ics 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 is(HcJ). They are express
13、ed in percent change per degreeCelsius, %/C, or the numerically equivalent percent perKelvin, %/K. The change in magnetic characteristics isnonlinear, so it is necessary to specify the temperature rangeover which the coefficient applies.1This specification is under the jurisdiction of ASTM Committee
14、 A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.02 onMaterial Specifications.Current edition approved Nov. 1, 2016. Published November 2016. DOI:10.1520/A110216.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
15、rviceastm.org. For Annual Book of ASTMStandards volume information, 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 be
16、en the successor to the MMPA and both organizations(MMPA and IMA) no 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 C
17、700, West Conshohocken, PA 19428-2959. United States13.2.3 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 X6 for a more complete discussion.4. Classification4
18、.1 The classification of samarium cobalt permanent mag-nets is given in Table 1 and in Table X1.1 with cross-referenceto MMPA Standard No. 0100-00 and IEC 60404-8-1.5. Ordering Information5.1 Orders for parts conforming to this specification shallinclude the following information:5.1.1 Reference to
19、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 minimum values listed in the tables.5.1.4 Quantity required.5.1.5 The required magnetization state of the providedmaterial (unmagnetize
20、d, fully magnetized, magnetized andthermally stabilized, magnetized and then partially demagne-tized). This information should appear on the part drawingwhenever possible.5.1.6 Certification of magnetic property evaluation.5.1.7 Marking and packaging requirements.5.1.8 Exceptions to this specificati
21、on or special require-ments such as plating, coating, or functional testing as mutuallyagreed upon by the producer and user.6. Chemical Composition6.1 Samarium cobalt magnets should be specified primarilyby magnetic performance. Chemical composition can have aninfluence on both magnetic and physical
22、 characteristics butshould only be specified when other options are insufficient tomeet user requirements. Agreement on composition must bemutually arrived at by producer and user.TABLE 1 Samarium Cobalt Permanent Magnets: Minimum Magnetic Property RequirementsAASTM DesignationBMaximumEnergy Product
23、(BH)maxResidualInductionBrCoercive FieldStrengthHcBIntrinsic CoerciveField StrengthHcJkJ/m3(MGOe) mT (G) kA/m (Oe) kA/m (Oe)ANISOTROPIC SmCo 1:5S1-SA-115/1436 115 (14.4) 789 (7885) 567 (7125) 1436 (18050)S1-SA-120/1600 120 (15.1) 800 (8000) 620 (7791) 1600 (20106)S1-SA-129/2268 129 (16.2) 827 (8265)
24、 643 (8075) 2268 (28500)S1-SA-140/1200 140 (17.6) 920 (9200) 660 (8294) 1200 (15080)S1-SA-143/2268 143 (18.0) 855 (8550) 665 (8360) 2268 (28500)S1-SA-150/700 150 (18.8) 900 (9000) 600 (7540) 700 (8796)S1-SA-160/1200 160 (20.1) 920 (9200) 660 (8294) 1200 (15080)S1-SA-170/700 170 (21.4) 930 (9300) 600
25、 (7540) 700 (8796)S1-SA-179/1134 179 (22.5) 998 (9975) 722 (9073) 1134 (14250)ANISOTROPIC SmCo 2:17S2-SA-140/1000 140 (17.6) 900 (9000) 620 (7791) 1000 (12566)S2-SA-160/700 160 (20.1) 940 (9400) 600 (7540) 700 (8796)S2-SA-172/529 172 (21.6) 950 (9500) 454 (5700) 529 (6650)S2-SA-172/1966 172 (21.6) 9
26、50 (9500) 703 (8835) 1966 (24700)S2-SA-180/1000 180 (22.6) 1000 (10000) 680 (8545) 1000 (12566)S2-SA-180/1500 180 (22.6) 1000 (10000) 660 (8294) 1500 (18850)S2-SA-186/756 186 (23.4) 998 (9975) 680 (8550) 756 (9500)S2-SA-186/1966 186 (23.4) 1017 (10165) 737 (9263) 1966 (24700)S2-SA-200/700 200 (25.1)
27、 1050 (10500) 600 (7540) 700 (8796)S2-SA-200/1500 200 (25.1) 1050 (10500) 700 (8796) 1500 (18850)S2-SA-201/529 201 (25.2) 1036 (10355) 491 (6175) 529 (6650)S2-SA-201/1966 201 (25.2) 1045 (10450) 779 (9785) 1966 (24700)S2-SA-215/756 215 (27.0) 1045 (10450) 718 (9025) 756 (9500)S2-SA-215/1512 215 (27.
28、0) 1045 (10450) 779 (9785) 1512 (19000)S2-SA-215/1814 215 (27.0) 1045 (10450) 779 (9785) 1814 (22800)S2-SA-215/2268 215 (27.0) 1045 (10450) 779 (9785) 2268 (28500)S2-SA-220/756 220 (27.6) 1088 (10878) 718 (9025) 756 (9500)S2-SA-220/1500 220 (27.6) 1100 (11000) 600 (7540) 1500 (18850)S2-SA-220/1890 2
29、20 (27.6) 1088 (10878) 801 (10070) 1890 (23750)S2-SA-230/756 230 (28.9) 1107 (11068) 718 (9025) 756 (9500)S2-SA-230/1134 230 (28.9) 1107 (11068) 824 (10355) 1134 (14250)S2-SA-230/1512 230 (28.9) 1107 (11068) 824 (10355) 1512 (19000)S2-SA-230/1890 230 (28.9) 1107 (11068) 824 (10355) 1890 (23750)S2-SA
30、-236/756 236 (29.7) 1112 (11115) 718 (9025) 756 (9500)S2-SA-236/1134 236 (29.7) 1112 (11115) 832 (10450) 1134 (14250)S2-SA-236/1512 236 (29.7) 1112 (11115) 832 (10450) 1512 (19000)AMagnetic properties at 20 C (68 F).BThe ASTM designation conforms to the requirements of this specification and is of t
31、he form MM-TT-XX/YY where:MM = material (S1 = samarium cobalt 1:5; S2 = samarium cobalt 2:17),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
32、/m rounded to the nearest integer.A1102 1626.2 The general chemical constituents of samarium cobalt1:5 magnets are samarium and cobalt. Samarium cobalt 2:17magnets contain samarium, cobalt, iron, copper, and zirco-nium. Approximate chemical compositions are listed in TableX3.1 and are typical but no
33、t mandatory.6.3 In some grades of samarium cobalt 1:5, praseodymiumis used to substitute for a portion of the samarium to increasemaximum energy product (see Table X3.1 and Appendix X4).In either the 1:5 or 2:17 grades, substitution of a portion ofsamarium by gadolinium (or a combination of gadolini
34、um anddysprosium) will result in “temperature-stable” grades, thosewhich exhibit less change in flux output as a function oftemperature. These are generally made to customer specifica-tion and are not considered standard grades.7. Physical and Mechanical Properties7.1 Typical thermal and physical pr
35、operties are listed inTable X2.1 in Appendix X2.7.2 Physical density values are given for information pur-poses only and are not mandatory.7.3 Samarium cobalt magnets are used for their magneticcharacteristics. The end-use application should not rely onthem for structural purposes due to low tensile
36、 and flexuralstrength. These materials are brittle, and can chip or breakeasily. Magnetic properties may also be affected by physicalstress.7.4 Strength testing of brittle materials such as samariumcobalt is difficult, expensive, and time-consuming and theremay be considerable scatter in the measure
37、d values. Producerstypically make these measurements at the onset of productionand they are seldom repeated.8. Magnetic Property Requirements8.1 Magnetic properties are listed in Table 1.8.2 The values of essential magnetic properties listed in thetable are specified minimum values at 20 6 2 C (68 6
38、 4 F),determined after magnetizing to saturation in closed magneticcircuit.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
39、 the axis ofpreferred orientation.8.4 Because of the nature of permanent magnet production,magnetic testing of each lot is recommended, especially forapplications where the magnet performance is closely speci-fied. Such magnetic property evaluations shall be conducted inthe manner described below. W
40、here the magnet shape is notsuitable for magnetic testing, a specimen shall be cut from themagnet 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 A977/A9
41、77M, or by using a suitable,mutually agreed upon magnetometric method.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 saturation and testing of the magnet
42、icproperties from the fully magnetized condition.8.4.3 When magnets are being purchased in the unmagne-tized condition or in an unknown state of magnetization, thetest laboratory shall magnetize the test specimen(s) to satura-tion in the same orientation as the received specimens indi-cated directio
43、n of magnetization and measure the magneticproperties from this fully magnetized condition.8.4.4 When magnets are being purchased in a calibrated,stabilized, or “knocked-down” condition, magnets should behandled with care to prevent exposure to externally appliedfields. Refer to Appendix X6 for an e
44、xplanation of these terms.During testing using Test Method A977/A977M, to avoidchanging the magnetization state of the material prior to test,the measurement should proceed in the second quadrant only,without attempting to saturate the magnet specimen.8.4.5 Other test methods may be utilized as agre
45、ed tobetween producer and user. Such tests may include the opencircuit magnetic field strength Helmholtz test, field strengthmeasurements in a defined magnetic circuit, or magnetic fieldstrength measurements adjacent to the magnet surface.9. Workmanship, Finish, and Appearance9.1 Dimensions and tole
46、rances shall be as specified on themagnet drawing and must be agreed upon between producerand user.9.2 Though porosity and voids are uncommon in samariumcobalt magnets, their appearance shall not in themselvesconstitute reason for rejection unless agreed upon betweenproducer and user. Allowable amou
47、nts of porosity and voidsshall be documented in writing and included as part of theordering or contracting process.9.3 Magnets shall be free of adhered magnetic particles andsurface residue which may interfere with assembly or properdevice function.9.4 Chips shall be acceptable if no more than 10 %
48、of anysurface identified as a magnetic pole surface is removed.9.5 Cracks visible to the naked eye shall not be permittedunless otherwise agreed to by producer and user.10. Sampling10.1 A lot shall consist of parts of the same form anddimensions, produced from a single mixed powder batch orsintering
49、 run, and from an unchanged process, without discon-tinuity in production, and submitted for inspection at one time.10.2 The producer and user shall agree upon a representa-tive number of specimens for testing. Typically, 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 Rehearing11.1 Parts that fail to conform to the requi
