1、Designation: B663/B663M 16Standard Specification forSilver-Tungsten Carbide Electrical Contact Material1This standard is issued under the fixed designation B663/B663M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This specification covers electrica
3、l contact componentsmade from silver-tungsten carbide materials by powder metal-lurgical processes.1.2 This specification covers compositions within the silver-tungsten carbide system normally specified by users of con-tacts.NOTE 1Table X1.1 and Table X1.2 in Appendix X1 provide a list oftypical com
4、positions used for various applications.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two sy
5、stems may result in non-conformancewith the standard.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 become familiarwith all hazards including those identified in the appropriateSafety D
6、ata Sheet (SDS) for this product/material as providedby the manufacturer, to establish appropriate safety and healthpractices, and determine the applicability of regulatory limi-tations prior to use.2. Referenced Documents2.1 ASTM Standards:2B328 Test Method for Density, Oil Content, and Intercon-ne
7、cted Porosity of Sintered Metal Structural Parts andOil-Impregnated Bearings (Withdrawn 2009)33. Significance and Use3.1 Proprietary methods for the manufacture of these mate-rials vary significantly among suppliers, and these methodsinfluence such properties as arc erosion, contact resistance, andt
8、he tendency to weld in service. Since the performance ofcontacts in a device depends on numerous factors outside thecontact itself (opening speed, closing speed, contact pressure,contact bounce, environmental variations, assembly techniqueand variations, etc.), this specification cannot ensure perfo
9、r-mance control in the application.As part of the qualification oninitial samples, it is recommended that the user functionallyand electrically test the materials for all devices applicable tothe materials use. This specification will provide a means forthe contact manufacturer and contact user to r
10、each agreementon the details of the material to be supplied for a specific use,and reasonable assurance that future lots will be similar inproperties and microstructure to the initial test or samplecontacts supplied.4. Ordering Information4.1 Orders for this material under this specification shallin
11、clude the following information:4.1.1 Dimensions (see Section 10),4.1.2 Chemical composition (see Table X1.1 and Table X1.2in Appendix X1 as a guideline),4.1.3 Physical properties (see Section 6 and Appendix X1 asa guideline),4.1.4 Certification (see Section 13), and4.1.5 Other features as agreed up
12、on between the manufac-turer and purchaser.5. Chemical Composition5.1 The material shall conform to composition limits asagreed upon between the manufacturer and the purchaser.5.2 The chemical analysis shall be made in accordance withthe methods prescribed in the newest edition of Volume 01.02of the
13、 Annual Book of ASTM Standards or by any otherapproved method agreed upon between the manufacturer andthe purchaser.6. Physical Properties6.1 The manufacturer and the purchaser shall agree onqualification tests for determination of physical properties.1This specification is under the jurisdiction of
14、 ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.05 on Precious Metals and Electrical Contact Materials.Current edition approved May 1, 2016. Published May 2016. Originallyapproved in 1979. Last previous edition approved in 2012 as B663 94 (2012)
15、.DOI: 10.1520/B0663/B0663M-16.2For referenced 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.3The last approved version of t
16、his historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.2 The tests shall be performed on production parts,wherever practical or applicable. (Small size contacts do notlend themselves to
17、accurate conductivity measurement.)6.3 The tests shall be determined after consideration of thefunction of the part.6.4 The typical properties of three most common types ofsilver-tungsten carbide contacts are given in Appendix X1.7. Dimensions, Mass, and Permissible Variations7.1 Permissible variati
18、ons in dimensions shall be within thelimits specified on drawings describing the contacts andaccompanying the order, or shall be within the limits specifiedin the purchase order.8. Finishing of Contacts8.1 The material shall be finished by such operations asnecessary to meet requirements agreed upon
19、 between themanufacturer and the purchaser of the contacts (braze alloybacking, tumbling to polish surfaces, special surface finish,silver-rich surface layer, cleaning, etc.).9. Workmanship, Finish, and Appearance9.1 The parts shall be free of defects in material orprocessing, that would seriously a
20、ffect their performance.10. Sampling10.1 LotUnless otherwise specified, a lot shall consist ofparts of the same form and dimensions, made of powders of thesame particle size range and composition, processed under thesame conditions, and submitted for inspection at the same time.10.2 Chemical Analysi
21、s10.2.1 At least one sample for chemical analysis shall betaken from each lot. A representative sample of chips may beobtained by milling, drilling, or crushing at least two pieceswith dry tools, without lubrication. In order to obtain oil freechips, the parts selected for test shall have the oil ex
22、tracted inaccordance with Test Method B328, if necessary.10.2.2 These specification limits do not preclude the pos-sible presence of other unnamed elements, impurities, oradditives. Analysis shall be regularly made only for the minorelements listed in the table. However, if a user knows ofelements t
23、hat might be detrimental to their application or hasother reasons for requiring analysis for specific elements, thenagreement between manufacturer and purchaser for both limitsand methods of analysis should be required for elements notspecified.10.3 Physical TestsThe manufacturer and the purchasersh
24、all agree on a representative number of specimens forphysical tests including microstructure.11. Inspection11.1 Unless otherwise specified, inspection of parts suppliedon contract shall be made by the purchaser.12. Rejection12.1 Unless otherwise specified, rejections based on testsmade in accordance
25、 with the specification shall be reported tothe manufacturer within 30 days of the receipt of the shipment.13. Certification13.1 A certification, when requested by the user, based onthe manufacturers quality control that the material conforms tothe requirements of this specification, shall be furnis
26、hed uponrequest of the purchaser, provided the request is made at thetime of cost quotation and at the time of order placement.14. Keywords14.1 arcing contacts; contacts; electrical contacts; powdermetallurgy; silver; silver tungsten carbide; tungsten carbide;tungsten carbide silverAPPENDIX(Nonmanda
27、tory Information)X1. TYPICAL PROPERTY VALUESX1.1 The following information provides guidelines forusers and manufacturers of silver-tungsten carbide contactmaterial. Typical ranges of chemistry and properties are givenfor the three most popular compositions, 40 % silver/60 %tungsten carbide, 50 % si
28、lver/50 % tungsten carbide, 65 %silver/35 % tungsten carbide. These properties are influencedby the particle size, shape, and distribution of tungsten carbide,homogeneity, impurities or additives, and other manufacturingprocess variables.NOTE X1.1Table X1.1 and Table X1.2 represent the major manufac
29、-turing techniques used in industry. The size and shape of the part isimportant in choosing the optimum technique as well as other consider-ations such as frequency of operation of the device, and how crucial is itsapplicationX1.1.1 The best choice for a given application should bemutually decided b
30、etween the purchaser and the manufacturerusing their mutual experience and application engineeringknowledge.X1.2 With the knowledge that several types are available,care should be taken to ensure that production lots are the samein all respects as samples and that if a seller change is made,noticeab
31、le property or performance variations are possible.B663/B663M 162ASTM 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 su
32、ch patent rights, and the riskof infringement 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 invit
33、ed either for revision of this standard 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
34、 fair hearing you shouldmake your views 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
35、 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Dr
36、ive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ X1.1 Typical Chemical Ranges Infiltrated Silver-Tungsten Carbide ContactsComposition,AWeight, %Class A Class B Class CSilver 38 to 42 48 to 52 63 to 67Tungsten carbide balance balance balanceCopper, max 0.5 0.5 0.5Cobalt or nickel, max 0.5 0.5 0.5T
37、otal impurities, max 1 1 1Typical PropertiesClass A Class B Class CHardness, Rockwell B 95 to 105 86 to 96 50 to 65Density, Mg/m313.1 12.6 11.9Electrical conductivity, % IACS 35 to 40 45 to 50 55 to 60Theoretical density, min, % 96 96 96PropertiesClass A Class B Class CModulus of rupture:BpsiMPa120
38、00082795 00065580 000552Youngs modulus:BpsiGPa561063865010634536106248Tensile strength:BpsiMPa55 00037940 00027639 500272Coefficient of expansion:Bin./in.Fm/mK7.610613.7 1068.25 10614.8 1069.45 10617106Thermal conductivity:BBtuin.hft2FW/mK280840543926334968716AAnalysis is regularly made for the elem
39、ents for which specific limits are listed. If, however, the presence of “other” elements is suspected or indicated in the course ofroutine analysis, further analysis shall be made to determine that the total of these “other” elements and the listed impurities are not in excess of the total impuritie
40、s limit.BItems that are normally useful for engineering calculations in contact design but are not specified.TABLE X1.2 Typical Chemical Ranges Press, Sintered, and Repressed Silver-Tungsten Carbide ContactsCompositionAWeight, %Class A Class B Class CSilver 38 to 42 48 to 52 63 to 67Tungsten carbide
41、 balance balance balanceCopper, max 0.2 0.2 0.2Nickel or cobalt, max 0.2 0.2 0.2Total impurities, max 0.5 0.5 0.5Typical PropertiesClass A Class B Class CHardness, Rockwell B (as repressed) 60 to 70 60 to 70 40 to 55Hardness, Rockwell B (annealed) 55 to 65 55 to 65 35 to 45Density, Mg/m313.1 12.6 11
42、.9Theoretical density, min,% 95 95 95Modulus of ruptureBpsi 70 000 62 000 60 000MPa 483 427 414AAnalysis is regularly made for the elements for which specific limits are listed. If, however, the presence of “other” elements is suspected or indicated in the course ofroutine analysis, further analysis shall be made to determine that the total of these “other” elements and the listed impurities are not in excess of the total impurities limit.BItems that are normally useful for engineering calculations in contact design but are not specified.B663/B663M 163
