ASTM_B_693_-_91_2012.pdf

Designation:B69391(Reapproved 2012)Standard Specification forSilver-Nickel Electrical Contact Materials1This standard is issued under the fixed designation B693;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 specification covers electrical contact componentsmade from silver nickel by powder metallurgical procedures.1.2 This specification covers compositions within the silver-nickel system normally specified by users of electrical con-tacts.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 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:2B328 Test Method for Density,Oil Content,and Intercon-nected Porosity of Sintered Metal Structural Parts andOil-Impregnated Bearings(Withdrawn 2009)3E18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE384 Test Method for Knoop and Vickers Hardness ofMaterials3.Ordering Information3.1 Orders for this material under this specification shallinclude the following information.3.1.1 Dimensions(see Section 6).3.1.2 Chemical composition(see reference table in Appen-dix X1).3.1.3 Physical properties(see Section 5 and reference tablein Appendix X1).3.1.4 Certification(see Section 13).3.1.5 Other features as agreed upon between the seller andthe user.4.Chemical Composition4.1 The material shall conform to composition limits asagreed upon between the manufacturer and user.4.2 The chemical analysis shall be made in accordance withthe methods described in the newest edition of Annual Book ofASTM Standards,Vol 03.05 and 03.06,or by any otherapproved method agreed upon between manufacturer andpurchaser.5.Physical Requirements5.1 The manufacturer and purchaser shall agree on qualifi-cation tests for determination of physical properties.5.2 The tests shall be performed on production parts,wherever practical,or applicable.(Small size contacts do notlend themselves to accurate conductivity measurement.)5.3 The tests shall be determined after consideration of thefunction of the part.5.4 The typical properties of the most common types ofsilver-nickel electrical contact materials are given in theappendix.6.Dimensions,Mass,and Permissible Variations6.1 Permissible variations 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.7.Workmanship,Finish,and Appearance7.1 The parts shall be free of defects in material orprocessing,which would seriously affect their performance.8.Sampling8.1 LotUnless otherwise specified,a lot shall consist ofparts of the same form,and dimensions,made of powders of1This 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 Electrical Contact Materials.Current edition approved May 1,2012.Published May 2012.Originallyapproved in 1981.Last previous edition approved in 2006 as B693 91(2006).DOI:10.1520/B0693-91R12.2For 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 this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the same particle size range and composition,processed underthe same conditions,and submitted for inspection at one time.9.Number of Tests and Retests9.1 Chemical AnalysisThe manufacturer and purchasershall agree on a representative number of specimens forchemical analysis.A representative sample of chips may beobtained by milling,drilling,or crushing with dry tools,(without lubrication).In order to obtain free chips,the partsselected for test shall have the oil extracted in accordance withTest Method B328,if necessary.9.2 Physical TestsThe manufacturer and purchaser shallagree on a representative number of specimens,for physicaltests including microstructure.10.Significance and Use10.1 Proprietary methods for manufacture of these materialsvary significantly among suppliers and these methods influencesuch properties as arc erosion,contact resist