ASTM_B_613_-_76_2012.pdf

Designation:B61376(Reapproved 2012)Standard Guide forPreparing Specifications for Miniature Brushes ofComposite Materials for Sliding Electric Contacts1This standard is issued under the fixed designation B613;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year 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 guide defines the criteria for composition,properties,and other requirements for brushes containing amatrix of one or more conducting metallic elements or alloysand one or more lubricating lamellar solids.1.2 The resulting specification is intended for use where thesize(for example,5 by 3 by 2 mm),shape,or other factorspreclude the determination of properties on specimens of thebulk material from which individual brushes are made.1.3 The requirements recommended herein have been foundto be desirable for most brush material composites.Care mustbe taken in preparing a specification for a pre-existing materialthat imposition of one or more provisions herein does not alterthe material or its performance.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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 appropriateMaterial Safety Data Sheet(MSDS)for this product/materialas provided by the manufacturer,to establish appropriatesafety and health practices,and determine the applicability ofregulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE384 Test Method for Knoop and Vickers Hardness ofMaterials2.2 ANSI Standard:C64.1 Brushes for Electrical Machines33.Requirements3.1 CompositionEach constituent should be listed indi-vidually by weight percent including tolerances if mutuallyagreed upon by producer and user.Any analytical techniquemay be used as agreed upon between the producer and user.3.2 DensityAn apparent density for the material should bedefined.The measurement and weight method defined byANSI C64.1 is preferred.3.3 ResistivityThe resistivity should be defined for at leastone axis.The procedure defined by ANSI C64.1 may need tobe modified,as agreed upon between the producer and user,forvery small brushes.3.4 HardnessThe bulk hardness of the brush materialshould be defined.Rockwell superficial hardness tests,18or14in.-ball,(Test Methods E18)and Knoop,500-g load(TestMethod E384)have been used.3.5 StrengthThe strength of the brush material should bedefined.Transverse strength(ANSI C64.1)may be used whenthe brushes are sufficiently large.Small brushes(for example,5 by 3 by 2 mm)will require that other test procedures be used(for example,shear strength).3.6 MicrostructureAll should be visually free of structuraldefects,cracks,etc.,upon examination at 50.The pressingdirection,as evidenced by laminations,should be as defined bythe purchase order.4.Keywords4.1 brushes;composite materials;electrical contacts;slidingcontacts1This guide is under the jurisdiction of ASTM Committee B02 on NonferrousMetals and Alloys and is the direct responsibility of Subcommittee B02.05 onPrecious Metals and Electrical Contact Materials.Current edition approved May 1,2012.Published May 2012.Originallyapproved in 1976.Last previous edition approved in 2006 as B613 76(2006).DOI:10.1520/B0613-76R12.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 ASTM 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 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 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 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 fair hearing you shouldmake your views