1、Designation: B 886 03Standard Test Method forDetermination of Magnetic Saturation (Ms) of CementedCarbides1This standard is issued under the fixed designation B 886; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope *1.1 This test method covers the determination of magneticsaturation (Ms) of cemented carbide powder materials andsintered pr
3、oducts using magnetic saturation induction testinstrumentation.1.2 The values stated in SI units are to be regarded as thestandard.1.3 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 establi
4、sh appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:A 340 Terminology of Symbols and Definitions Relating toMagnetic Testing2B 243 Terminology of Powder Metallurgy3E 1316 Terminology for Nondest
5、ructive Examinations43. Terminology3.1 Definitions:3.1.1 For definition of terms used in this procedure refer toTerminology A 340, Terminology B 243, and TerminologyE 1316.3.1.2 dcdirect current.4. Summary of Test Method4.1 A test specimen is statically positioned in the magneticfield generated by d
6、c coils or a permanent magnet and sensingcoils of the test apparatus. The specimen is magnetized toinduction saturation by the field and translated linearly that theintrinsic magnetic moment of the specimens binder phaseinduces a d-c current to flow in the sensing coils of the testapparatus. The in
7、duced currect is proportional to the amount ofmagenetic binder phase present in the test specimen. Measure-ment of the induced current permits calculation of the intrinsicmagnetic saturation of the test sample.5. Significance and Use5.1 This test method allows the non-destructive measure-ment of the
8、 magnetic fraction of the binder phase in cementedcarbide powder materials and sintered product, and may beused as an indirect measure of the carbon level in the materialor product.5.2 Measurement of magnetic saturation provides a com-parison of the relative fraction of magnetic binder phase that is
9、cobalt, nickel, or iron, present in the material and can be usedfor acceptance of product to specification.5.3 Measurement of magnetic saturation can be used as ameasure of the quality of powder material.6. Interferences6.1 No direct absolute measurement of magnetic saturationcan be made. The measu
10、rement is a relative comparison ofstandard reference materials.6.2 Measurement of magnetic saturation is a non-destructive “bulk” measurement which is averaged over thetest specimen volume. The technique cannot be used to inferanything regarding the relative distribution of the binder phasewithin th
11、e test sample.6.3 Measurement of magnetic saturation is affected by testsample size and shape, especially aspect ratio, and the compo-sition of the binder phase, that is, a mixture of ferromagneticelements of varying intrinsic magnetic moments6.4 Small test samples or test samples containing relativ
12、elylow concentrations of the binder phase may be immeasurablein that the low concentration prohibits detection by the fieldsensing coils of the specific apparatus employed.7. Apparatus7.1 Instrumentation capable of inducing magnetic saturationand then sensing the inherent intrinsic magnetic moment o
13、f themagnetic fraction of the binder phase.1This test method is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.06 on Cemented Carbides.Current edition approved April 10, 2003. Published May 2003. Originally
14、approved in 1998. Last previous edition approved in 1998 as B 88698.2Annual Book of ASTM Standards, Vol 03.04.3Annual Book of ASTM Standards, Vol 02.05.4Annual Book of ASTM Standards, Vol 03.03.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr
15、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Balance having a capacity of 200 g and a sensitivity of0.001 g.8. Standards8.1 No certified cemented carbide standards, powder mate-rials or sintered product, are available for magnetic saturationmeasurement. Most common
16、practice is the development of(internal) reference materials representative of the test samplesbeing evaluated.8.2 Pure ferromagnetic materials such as cobalt (Co), iron(Fe), or Nickel (Ni), and iron oxide, that is, Fe3O4, with knownmagnetic moments are recommended for calibration of theinstrumentat
17、ion.9. Test Specimen9.1 Test specimens may be in the form of sintered solids,unsintered powder compacts, or encapsulated powders of a sizesuitable to fit into the specimen holder of the apparatus. Thelong axis of the specimen should be perpendicular to themagnetic field of the test apparatus.10. Pro
18、cedure10.1 For commercial instrumentation, refer to the equip-ment manufacturers operating manual and follow operatinginstructions.10.2 Obtain the mass of each test specimen.10.3 Position the test sample in the center of the magneticfield/sensing coils.10.4 Saturate the test specimen.10.5 Remove/tra
19、nslate the test specimen in the sensingcoils.10.6 Read and record the value of the intrinsic magneticsaturation from the test apparatus. Measurement units areTesla-m3per kilogram (emu per gram (csg).10.7 Relative percent of magnetic saturation of the testsample may be calculated and reported. Consid
20、eration must begiven to the composition of the binder phase with respect toferromagnetic components, and the presence of other metallicconstituents, for example, chromium (Cr) in the powdermaterial or sintered product, that would affect the binder phasecomposition or magnetic moment of the constitue
21、nts.10.8 Repeat measurements can be made to obtain an aver-age value and range of values for test specimens of asymmetricshape. Orientation of the test sample should be changed withinthe test apparatus sample chamber for each repeat measure-ment.11. Report11.1 Report magnetic saturation as Tesla-m3p
22、er kilogram(emu per gram), or as relative percent, (that is, magneticportion of the binder phase/total mass of binder phase in testsample).12. Precision and Bias12.1 PrecisionMeasurement of magnetic saturation is arelative comparison against well characterized reference mate-rials of similar composi
23、tion and mass (see 8.1). No statementabout precision can be made due to the effects of test specimensize and shape, variations in the binder phase composition thatare within material or product specification, and the effect ofvariations of the carbon content of the test samples (see 6.3).12.2 BiasMe
24、asurement of magnetic saturation is a rela-tive comparison against well characterized reference materialsof similar composition and mass (see 8.1). No statement aboutbias can be made due to the affects of test specimen size andshape, variations in the binder phase composition that arewithin material
25、 or product specification, and the affect ofvariations of the carbon content of the test samples (see 6.3).13. Keywords13.1 cemented carbide; magnetic saturation (Ms)SUMMARY OF CHANGESCommittee B09 has identified the location of selected changes to this standard since the last issue (B 886 98) that
26、may impact the use of this standard.(1) The use of a permanent magnet to induce saturation wasadded.(2) The word “or” was added in Section 5.2. It has beendetermined that mixtures of nickel, cobalt, and iron in sinteredcarbides will produces alloys of various amounts whoseintrinsic magnet moment is
27、different than the sum of theindividual binder materials.(3) The units were changed to SI units as the standard unit inSections 10.6 and 11.(4) The reference to vanadium affecting the magnetic momentof the binder material was removed, because vanadium doesnot affect magnetic saturation determination
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29、ghts, 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 standard or for additiona
30、l 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 views known to the AST
31、M 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).B886033
