ASTM_B_628_-_98_2016.pdf

Designation:B62898(Reapproved 2016)Standard Specification forSilver-Copper Eutectic Electrical Contact Alloy1This standard is issued under the fixed designation B628;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This specification covers 72%silver-28%copper(eu-tectic)alloy rod,wire,strip,and sheet material for electricalcontacts.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 become familiarwith all hazards including those identified in the appropriateSafety Data 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:2B277 Test Method for Hardness of Electrical Contact Mate-rialsB476 Specification for General Requirements for WroughtPrecious Metal Electrical Contact Materials3.General Requirements3.1 Specification B476 and Test Method B277 shall apply toall materials produced to this specification.4.Manufacture4.1 Raw materials shall be of such quality and purity thatthe finished product will have the properties and characteristicsprescribed in this specification.4.2 The material shall be finished by such operations(coldworking,heat treating,annealing,turning,grinding,or pick-ling)as are required to produce the prescribed properties.5.Chemical Composition5.1 Material produced under the specification shall conformto the requirements as to chemical composition prescribed inTable 1.6.Mechanical Requirements6.1 The material shall conform to the mechanical propertiesprescribed in Table 2 or Table 3.6.2 All test specimens shall be full thickness or diameterwhen practical.6.3 All tests are to be conducted at room temperature,about68F(20C).7.Inspection and Testing7.1 Material furnished under this specification shall beinspected by the manufacturer as detailed in the applicableprovisions of Specification B476 and as listed below.7.1.1 Visual inspection at 10.7.1.2 Temper test(hardness or tension,but not both).Atension test is recommended for strip below 0.030-in.(0.8-mm)thickness and for wire of any diameter.A tension test ispreferred when permitted by part size and quantity.7.1.3 Dimensional tests.7.1.4 Spectrographic or chemical analysis when indicatedby the purchase order.8.Keywords8.1 composition;electrical contacts;impurities;preciousmetals;silver copper alloy1This 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 1,2016.Published May 2016.Originallyapproved in 1977.Last previous edition approved in 2010 as B628 98(2010).DOI:10.1520/B0628-98R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 TABLE 2 Mechanical Properties of Sheet and StripTemperReduction in B&SNumbers(Reference)PercentReduction(Reference)Ultimate Tensile Strength,psi(MPa)MinimumElongationin 2 in.,%Hardness,Rockwell 30 TMinimumMaximumA0045 00055 000155664(310)(380)1 4H11156 00066 00076169(390)(460)1 2H22160 00070 00036472(410)(480)3 4H32966 00076 00026573(460)(520)Hard43769 00079 00026674(480)(550)Extra hard65075 00085 00016775(520)(590)Spring86083 00093 00016876(570)(640)TABLE 3 Mechanical Properties of Wire and RodTemperReduction in B&SNumbers(Reference)PercentReduction(Reference)Ultimate Tensile Strength,psi(MPa)MinimumElongationin 2 in.,%MinimumMaximumA0045 00055 00015(310)(380)1 8H121152 00062 0007(360)(430)1 4H12158 00068 0005(400)(470)1 2H23765 00075 0004(450)(520)3 4H35070 00080 0004(480)(550)Hard46076 00086 0003(520)(590)Extra hard67585 00095 0002(590)(660)Spring88495 000105 0002(660)(724)Extra spring1090105 000115 0001(724)(793)TABLE 1 Chemical CompositionAElementWeight%Silver71.0 to 73.0CopperbalanceTotal of all impurities0.15Zinc0.06 maxIron0.05 maxCadmium0.05 maxLead0.03 maxNickel0.01 maxAluminum0.005 maxPhosphorus0.03 maxTotal others0.06 maxAAnalysis is regularly made for the elements for which specific limits are listed.If,however,the p