1、Designation: B664 90 (Reapproved 2012)Standard Specification for80 % Silver-20 % Graphite Sliding Contact Material1This standard is issued under the fixed designation B664; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f 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 defines the criteria for compositionand other requirements for brushes with a nominal silverconte
3、nt of 80 %, by weight, with the balance being substan-tially graphite.1.2 The values stated in inch-pound units are to be regardedas standard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with i
4、ts use. It is theresponsibility of the user of this standard to become familiarwill all hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer, to establish appropriatesafety and health practices, and determine
5、the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B613 Guide for Preparing Specifications for MiniatureBrushes of Composite Materials for Sliding Electric Con-tactsE18 Test Methods for Rockwell Hardness of Metallic Ma-terials2.2 ANSI Standard:C64.1 Br
6、ushes for Electrical Machines33. Requirements3.1 Chemical Composition, shall be as follows:Silver 80 6 3 % (weight)Graphite balanceTotal metal impurities 1 % maxPercent ash in graphite (ANSI C64.1) 5 % max3.2 Physical PropertiesThe following lot average proper-ties must be met. Unless otherwise agre
7、ed between the pro-ducer and the user, the number of samples shall be five.3.2.1 DensityThe minimum acceptable density shall be5.15 g/cm3as determined by the measurement and weightmethod defined by ANSI C64.1.3.2.2 Shear Strength:3.2.2.1 The shear strength for the normal and transversedirections sha
8、ll be measured for rectangular parallelepipedsand shall be 2000 psi (14 MPa), minimum.3.2.2.2 The shear strength for the longitudinal shear direc-tion shall be measured for cylinders and shall be 1000 psi (6.9MPa), minimum.3.3 MicrostructureParts shall be visually free of structuraldefects, cracks,
9、etc., upon examination at 503. The pressdirection, as evidenced by laminations, shall be as defined bythe purchase order. Also the brush material shall not containabrasive particles that will sliver a metal alloy ring with ahardness$110 HK100when the brush force is equal to 30 g orthat necessary for
10、 5.0 psi (34 kPa) pressure, whichever isgreater. A sliver is defined as a loose wear particle with onedimension $503 the next smaller dimension. Although sliv-ering can be caused by coarse abrasive particles, other param-eters can contribute to slivering (for example, very high brushforce).3.4 Sourc
11、e or grade of raw materials (for example, graphite)or methods of manufacture shall not be changed withoutnotifying users.1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.05 on Precious Metals and El
12、ectrical Contact Materials.Current edition approved May 1, 2012. Published May 2012. Originallyapproved in 1979. Last previous edition approved in 2006 as B664 81 (2006).DOI: 10.1520/B0664-90R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
13、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr
14、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Reference Properties4.1 Because of their size, the following properties forminiature brushes cannot always be determined; however,these properties are typical for larger parts.4.1.1 Superficial HardnessThe typical Rockwel
15、l superfi-cial hardness for this material is 44 R15W as determined byTest Method E18 with a18-in. steel ball.4.1.2 Specific ResistanceThe typical specific resistancefor the material is 4 3 106V-in. (1 3 107V-m) as determinedby the method detailed in ANSI C64.1.5. Certification5.1 Material supplied u
16、nder this specification shall be cer-tified as meeting the requirements of this specification by theproducer of the material.6. Keywords6.1 electrical contacts; graphite; silver; sliding contactsASTM International takes no position respecting the validity of any patent rights asserted in connection
17、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 infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible te
18、chnical 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 additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consider
19、ation 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 ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr
20、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B664 90 (2012)2
