【astm標(biāo)準(zhǔn)】b 799 - 95 (2014)

1、Designation:B799?95(Reapproved2014)StardTestMethodfPosityinGoldPalladiumCoatingsbySulfurousAcidSulfurDioxideVap1ThisstardisissuedunderthefixeddesignationB799thenumberimmediatelyfollowingthedesignationindicatestheyearofig

2、inaladoptioninthecaseofrevisiontheyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperepsilon()indicatesaneditialchangesincethelastrevisionreapproval.1.Scope1.1Thistestmethodcoversequipmentmetho

3、dsfdeterminingtheposityofgoldpalladiumcoatingsparticularlyelectrodepositscladmetalsusedonelectricalcontacts.1.2Thistestmethodisdesignedtoshowwhetherthepositylevelislessgreaterthansomevaluewhichbyexperienceisconsideredbyt

4、heusertobeacceptableftheintendedapplication.1.3Avarietyofotherpositytestingmethodsaredescribedintheliterature.23OtherpositytestmethodsareB735B741B798B809.AnASTMGuidetotheionofpositytestsfelectrodepositsrelatedmetalliccoa

5、tingsisavailableasGuideB765.1.4ThevaluesstatedinSIunitsaretoberegardedasstard.Thevaluesgiveninparenthesesarefinfmationonly.1.5Thisstarddoesnotpurpttoaddressallofthesafetyconcernsifanyassociatedwithitsuse.Itistheresponsib

6、ilityoftheuserofthisstardtobecomefamiliarwithallhazardsincludingthoseidentifiedintheappropriateMaterialSafetyDataSheet(MSDS)fthisproductmaterialasprovidedbythemanufacturertoestablishappropriatesafetyhealthpracticesdeterm

7、inetheapplicabilityofregulatylimitationspritouse.FspecifichazardsseeSection6.2.ReferencedDocuments2.1ASTMStards:4B374TerminologyRelatingtoElectroplatingB542TerminologyRelatingtoElectricalContactsTheirUseB735TestMethodfPo

8、sityinGoldCoatingsonMetalSubstratesbyNitricAcidVapB741TestMethodfPosityInGoldCoatingsOnMetalSubstratesByPaperElectrography(Withdrawn2005)5B765GuidefionofPosityGrossDefectTestsfElectrodepositsRelatedMetallicCoatingsB798Te

9、stMethodfPosityinGoldPalladiumCoatingsonMetalSubstratesbyGelBulkElectrographyB809TestMethodfPosityinMetallicCoatingsbyHuSulfurVap(“FlowersofSulfur”)3.Terminology3.1Definitions—ManytermsusedinthistestmethodaredefinedinTer

10、minologyB542termsrelatingtometalliccoatingsaredefinedinTerminologyB374.3.2DefinitionsofTermsSpecifictoThisStard:3.2.1crosionproductsn—thosereactionproductsemanatingfromthepesthatprotrudefromareotherwiseattachedtothecoati

11、ngsurfaceafteravaptestexposure.3.2.2measurementarea(“significantsurface”)n—thesurfacethatisexaminedfthepresenceofposity.Thesignificantsurfacesmeasurementareasoftheparttobetestedshallbeindicatedonthedrawingofthepartbyprov

12、isionofsuitablymarkedsamples.3.2.2.1Discussion—Fspecificationpurposesthesignificantsurfacesmeasurementareasareoftendefinedasthose1ThistestmethodisunderthejurisdictionofASTMCommitteeB02onNonferrousMetalsAlloysisthedirectr

13、esponsibilityofSubcommitteeB02.11onElectricalContactTestMethods.CurrenteditionapprovedOct.12014.PublishedOctober2014.iginallyapprovedin1988.Lastpreviouseditionapprovein2009asB799–95(2009).DOI:10.1520B079995R14.2Fexamples

14、ee:NobelF.J.OstrowB.D.ThompsonD.W.“PosityTestingofGoldDeposits”PlatingVol521965p.1001.3KrumbienS.J.“PosityTestingofContactPlatings”ProceedingsConnectsInterconnectionTechnologySymposiumOct.1987p47.4FreferencedASTMstardsvi

15、sittheASTMwebsitewww.astm.gcontactASTMCustomerServiceat.FAnnualBookofASTMStardsvolumeinfmationrefertothestard’sDocumentSummarypageontheASTMwebsite.5Thelastapprovedversionofthishisticalstardisreferencedonwww.astm.g.Copyri

16、ght?ASTMInternational100BarrHarbDrivePOBoxC700WestConshohockenPA194282959.UnitedStates1areessentialtotheserviceabilityfunctionofthepartsuchasitscontactpropertieswhichcanbethesourceofcrosionproductstarnishfilmsthatinterfe

17、rewiththefunctionofthepart.Thesignificantsurfacesshallbeindicatedonthedrawingsofthepartsbytheprovisionofsuitablymarkedsamples.6.SafetyHazards6.1Carryoutthesetestproceduresinacleanwkingfumehood.TheSO2gasthatisemittedistox

18、iccrosiveirritating.6.2Usecautionhoweverinactuallyperfmingtheteststhatthedraftsoftenfoundinhoodsdonotcausesignificantcoolingofthechamberwallswhichmayleadtocondensationofwateraccelerationofthetest.Itisoftenconvenienttoenc

19、losethereactionvesselinaboxwithaloosefittingcovertokeeptheboxinahoodduringthetest.6.3Observenmalprecautionsinhlingcrosiveacids.Inparticularweareyeprotectioncompletelyenclosingtheeyesmakeeyewashfacilitiesreadilyavailable.

20、7.Apparatus7.1TestChamber—Maybeanyconvenientsizeglassacrylicresinvesselhavingagastightlidsuchasaglassdesiccatof9to10Lcapacity.Theratioofchambervolumeincubiccentimeterstothegeneratingsolution(sulfurousacid)surfaceareainsq

21、uarecentimetersshallnotexceed2561.7.2SpecimenHoldersSuppts—Maybemadeofglasspolytetrafluoethyleneotherinertmaterials.Itisessentialthatthespecimensbearrangedsoasnottoimpedecirculationofthegas.Specimensshallnotbecloserthan2

22、5mm(1in.)fromthewall75mm(3in.)fromthesolutionsurface.Alsothemeasurementareasofthespecimensshallbeatleast12mm(0.5in.)fromeachother.7.2.1Donotuseapcelainplateanyotherstructurethatwouldcovermethan30%oftheliquidsurfacecrosss

23、ectionalarea.Thisistoinsurethatmovementofairvapwithinthevesselwillnotberestrictedduringthetest.7.3Stereomicroscopehavinga10magnificationshallbeusedfpecounting.Inadditionamovablesourceofilluminationcapableofgivingobliquel

24、ightingonthespecimensurfaceisrequired.Itispreferredthatagraduatedreticlebefittedintooneoftheeyepiecesofthemicroscope.8.Reagents8.1SulfurousAcid(H2SO3)“analyzedreagentgrade”betterpreferablyinindividualsealed500mLbottles.9

25、.Procedure9.1Hlespecimensaslittleaspossibleonlywithtweezersmicroscopelenstissuecleansoftcottongloves.Pritothetestinspectthesamplesunder10magnificationfevidenceofparticulatematter.Ifpresentsuchparticlesshallberemovedbyblo

26、wingthemwithcleanoilfreeair.Ifthisisnotsuccessfuldiscardthesample.ThencleanthesampleswithsolventssolutionsthatdonotcontainchlinatedhydrocarbonsCFCsotherknownozonedestroyingcompounds.TheprocedureoutlinedinNote1hasbeenfoun

27、dtogivesatisfactyresultsfplatingswithmildtomoderatesurfacecontamination.NOTE1—Suggestedcleaningprocedure:(1)Keepindividualcontactsseparatedifthereisapossibilityofdamagetothemeasurementareasduringthevariouscleaningsteps.(

28、2)Cleansamplesf5mininanultrasoniccleanerwhichcontainsahot(65–85C)2%aqueoussolutionofamildlyalkaline(pH7.5–10)detergent(suchasMicroSparkleen).(3)Afterultrasoniccleaningrinsesamplesunderwarmrunningtapwaterfatleast5s.(4)Rin

29、sesamplesultrasonicallyf2mininfreshdeionizedwatertoremovethelastdetergentresidues.(5)Immerseinfreshmethanolisopropanolultrasonically“agitate”fatleast30sindertoremovethewaterfromthesamples.(6)Removedrysamplesuntilthealcoh

30、olhascompletelyevaporated.Ifanairblastisusedasanaidtodryingtheairshallbeoilfreecleandry.(7)Donottouchmeasurementareaofthesampleswithbarefingersaftercleaning.(8)Reinspectsamples(under10magnification)fparticulatematteronth

31、esurface.Ifparticulatesarefoundrepeatthecleaningsteps.Surfacecleanlinessisextremelyimptantcontaminantssuchasplatingsaltsganicfilmsmetalflakesmaygiveerroneousindicationsofdefectsareunacceptable.NOTE2—Omitthecleaningstepsf

32、sampleshavingcrosioninhibitinglubricantcoatingsbothifitisdesiredtodeterminetheefficacyofthesecoatingsintheSO2atmosphere.9.2Thetesttemperatureshallbe2363Cunlessotherwisespecifiedtherelativehuityintheimmediatevicinityofthe

33、testchambershallbenogreaterthan60%.Iftherelativehuityisgreaterthan60%donotrunthetest.9.3Carefullyaddthesulfurousacid(H2SO3)tothebottomofthecleandrytestchamberinafumehoodloadthesamplesusingsuitablefixturesreplacethelid.Th

34、eambientrelativehuityshallbenogreaterthan60%duringboththeadditionoftheH2SO3theionofthesamples.9.4Exposethesamplestothetestenvironmentf2hfgoldcoatingthicknessesof1.25m(50in.)greater90minfgoldthicknesseslessthan1.25m60minf

35、palladiumcoatings.9.5Removethesamplesattheendofthetestperiodallowthemtostabilizeatlowhuityunderthefumehoodf1065min.9.6Placesamples(preferablywiththeirholdingfixtureifpossible)intoanaircirculatingovenmaintainedat12565Cf15

36、65minfthepurposeof“developing”thepecrosionproductsfeasierexamination.9.7Discardthesulfurousacidinasafemannerattheendofeachday.Itmaybereusedduringanyonedayfseveralconsecutivetestsprovidedthechamberiskeptclosedbetweentestr

37、unsnodiscolationcontaminationvisibletothenakedeyeispresent.10.Examination10.1Countindividualpecrosionproductsat10magnificationusingcollimatedincescentilluminationatanobliqueanglebelow15.Theyaredelineatedbythecrosionprodu