1、 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 4524-2:2000 ICS 25
2、220.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Metallic coatings Test methods for electrodeposited gold and gold alloy coatings Part 2: Mixed flowing gas (MFG) environmental testsThis British Standard, having been prepared under the direction of the Sector Committee f
3、or Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 June 2000 BSI 06-2000 ISBN 0 580 34903 9 BS ISO 4524-2:2000 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO
4、4524-2:2000 and implements it as the UK national standard. It supersedes BS 6670-2:1986 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee STI/37, Methods of test for metallic and related coatings, which has the responsibility to: aid enquirers to unders
5、tand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on t
6、his committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using
7、 the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity f
8、rom legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 31 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.Referencenumber ISO45
9、24-2:2000(E) INTERNATIONAL STANDARD ISO 4524-2 Secondedition 2000-03-15 MetalliccoatingsTestmethodsfor electrodepositedgoldandgoldalloy coatings Part2: Mixedflowinggas(MFG)environmental tests Revtements mtalliques Mthodes dessai des dpts lectrolytiques dor et dalliage dor Partie 2: Essais climatique
10、s aux gaz mixtes coulement (MFG)ISO4524-2:2000(E) ii ISO4524-2:2000(E)iii Contents Page Foreword.iv Introduction.v 1 Scope1 2 Normativereferences1 3 Termsanddefinitions.2 4 Reagentsandmaterials2 5 Apparatus.3 6 Procedure.7 7 Testreport13 AnnexA(normative)Massgaincoupons.14 AnnexB(informative)Estimat
11、ingrequiredcorrosivegasexchangerate.18 AnnexC(normative)Coulometricreduction.19 AnnexD(informative)Surfaceanalysis28 AnnexE(normative)Resistancemonitoring.29 Bibliography31ISO4524-2:2000(E) iv Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies
12、ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaiso
13、nwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommittee
14、sarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthispartofISO4524maybethesubjectofpatent rights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatent
15、rights. InternationalStandardISO4524-2waspreparedbyTechnicalCommitteeISO/TC107, Metallic and other inorganic coatings, Subcommittee SC 7, Corrosion tests. Thissecondeditioncancelsandreplacesthefirstedition(ISO4524-2:1985),whichhasbeentechnicallyrevised. ISO4524consistsofthefollowingparts,underthegen
16、eraltitle Metallic coatings Test methods for electrodeposited gold and gold alloy coatings: Part 1: Determination of coating thickness Part 2: Mixed flowing gas (MFG) environmental tests Part 3: Electrographic tests for porosity Part 4: Determination of gold content Part 5: Adhesion tests Part 6: De
17、termination of the presence of residual salts AnnexesA,CandEformanormativepartofthispartofISO4524.AnnexesBandDareforinformationonly.ISO4524-2:2000(E)v Introduction Mixedflowinggas(MFG)testsareusedtosimulateoramplifyexposuretoenvironmentalconditionsthatelectrical contactsorconnectorscanbeexpectedtoex
18、perienceinvariousapplicationenvironments(seereferences2and 3). TestsamplesthathavebeenexposedtoMFGtestshaverangedfrombaremetalsurfaces,toelectricalconnectors andtocompleteassemblies. Thespecifictestconditionsareusuallychosensoastosimulate,inthetestlaboratory,theeffectsofcertain representativefielden
19、vironmentsorenvironmentalseveritylevelsonstandardmetallicsurfaces,suchascopper andsilvercouponsorporousgoldcoatings(seereferences2and3). BecauseMFGtestsaresimulations,boththetestconditionsandthedegradationreactions(chemicalreactionrate, compositionofreactionproducts,etc.)maynotalwaysresemblethosefou
20、ndintheserviceenvironmentofthe productbeingtested. TheMFGexposuresaregenerallyusedinconjunctionwithproceduresthatevaluatecontactorconnectorelectrical performancesuchasmeasurementofelectricalcontactresistancebeforeandafterMFGexposure. TheMFGtestsareusefulforconnectorsystems,thecontactsurfacesofwhicha
21、reelectroplatedorcladwithgold orotherpreciousmetalfinishes.Forsuchsurfaces,environmentallyproducedfailuresareoftenduetohigh resistancesorintermittencescausedbytheformationofinsulatingcontaminationinthecontactregion.This contamination,intheformoffilmsandhardparticles,isgenerallytheresultofporecorrosi
22、onproductmigrationor tarnishcreepagefromporesinthepreciousmetalcoatingandfromunplatedmetalboundaries,ifpresent.INTERNATIONALSTANDARD ISO4524-2:2000(E)1 MetalliccoatingsTestmethodsforelectrodepositedgoldand goldalloycoatings Part2: Mixedflowinggas(MFG)environmentaltests WARNINGThispartofISO4524doesno
23、tpurporttoaddressallofthesafetyproblems,ifany, associatedwithitsuse.ItistheresponsibilityoftheuserofthispartofISO4524toestablishappropriate safetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse. 1 Scope ThispartofISO4524providesproceduresforconductingmixedflowinggas(M
24、FG)environmentaltestsinvolving exposurestocontrolledquantitiesofcorrosivegasmixtures. Itdescribestherequiredequipmentandthemethodsforgas,temperatureandhumiditycontrolthatenableteststo beconductedinareproduciblemanner.Reproducibilityismeasuredthroughtheuseofcontrolcouponsthe corrosionfilmsofwhicharee
25、valuatedbymassgain,coulometryorbyvariouselectronandX-raybeamanalysis techniques.Reproducibilitycanalsobemeasuredby in situ corrosion rate monitors using electrical resistance or massfrequencychangemethods. MFGtestscanbeusedto: evaluatenovelelectricalcontactmetallizationforsusceptibilitytodegradation
26、duetoenvironmentalexposure tothetestcorrosivegases; evaluatetheshieldingcapabilityofconnectorhousingsthatmayactasabarriertotheingressofcorrosive gases; evaluatethesusceptibilityofotherconnectormaterialssuchasplastichousingstodegradationfromthetest corrosivegases. MFGtestsarenotnormally: usedasporosi
27、tytests(forguidanceonporositytesting,seeISO10308, Metallic coatings review of porosity tests); applicablewherethefailuremechanismisotherthanpollutantgascorrosionsuchasintin-coatedseparable contacts. 2 Normativereferences Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext
28、constituteprovisionsof thispartofISO4524.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthesepublications donotapply.However,partiestoagreementsbasedonthispartofISO4524areencouragedtoinvestigatethe possibilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.Forunda
29、ted references,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIECmaintain registersofcurrentlyvalidInternationalStandards.ISO4524-2:2000(E) 2 ISO3696:1987, Water for analytical laboratory use Specification and test methods. ISO4221:1980, Air quality Determination of mass conc
30、entration of sulphur dioxide in ambient air Thorin spectrophotometric method. ISO4677-1:1985, Atmospheres for conditioning and testing Determination of relative humidity Part 1: Aspirated psychrometer method. ISO4677-2:1985, Atmospheres for conditioning and testing Determination of relative humidity
31、 Part 2: Whirling psychrometer method. ISO6349:1979, Gas analysis Preparation of calibration gas mixtures Permeation method. ISO6767:1990, Ambient air Determination of the mass concentration of sulfur dioxide Tetrachloromercurate (TCM)/pararosaniline method. ISO7934:1989, Stationary source emissions
32、 Determination of the mass of concentration of sulfur dioxide Hydrogen peroxide/barium perchlorate/Thorin method. ISO7996:1985, Ambient air Determination of the mass concentration of nitrogen oxides Chemiluminescence method. ISO9096:1992, Stationary source emissions Determination of concentration an
33、d mass flow rate of particulate material in gas-carrying ducts Manual gravimetric method. ISO10313:1993, Ambient air Determination of the mass concentration of ozone Chemiluminescence method. ISO12687:1996, Metallic coatings Porosity tests Humid sulfur (flowers of sulfur) test. IEC60050, Internation
34、al Electrotechnical Vocabulary. 3 Termsanddefinitions ForthepurposesofthispartofISO4524,thetermsanddefinitionsrelatingtoelectricalcontactsgivenin IEC60050apply. 4 Reagentsandmaterials 4.1Waterforhumiditygeneration,equivalenttograde1orbetterofISO3696. 4.2Carriergas,suchasnitrogen.Itshallnotintroducer
35、eactiveconstituentsintothetestatmospheretoan amountofmorethan5%ofanyspecifiedcorrosivetestatmosphereconstituent. 4.3Cleanfilteredair,asrequiredformake-uptosupportthenecessaryexchangerate,inaccordancewith 6.6.7.1b),asspecifiedin5.3.2. 4.4Corrosivegases,chemicallypuregradeorequivalent. 4.5Corrosivitym
36、onitormaterials(CMMs),comprisedofthecouponsthatareexposedtothetestatmosphere formassgain(annexA),coulometricreductioninaccordancewithannexC,orresistancemonitoringinaccordance withannexE.ISO4524-2:2000(E)3 5 Apparatus 5.1 General ApparatusrequiredtoconductMFGtestsisdividedintofourmajorcategories:corr
37、osiontestchamber,gassupply system,chambermonitoringsystemandchamberoperatingsystem. 5.2 Corrosiontestchamber 5.2.1Thechambershallconsistofanenclosuremadeofnon-reactive,low-absorbing,non-metallicmaterials containedwithinacabinetorovencapableofmaintainingthetemperaturetoamaximumtoleranceof 1Cwitha pre
38、ferredtoleranceheldto 0,1Cwithintheusablechamberworkingspaceinaccordancewith6.3withameans ofintroducinganexhaustgasfromthechamber.Thechamberisolatesthereactivegasesfromtheexternal environment.Chambermaterialsthatarenotlow-absorbingcanaffecttestconditionsbyabsorbingoremitting reactivegases,leadingtoc
39、ontrolandreproducibilityproblems.Thechamberconstructionshallbesuchthatthe leakrateislessthan3%ofthevolumeexchangerate. 5.2.2Thechambershallhaveprovisionformaintaininguniformityoftheaveragegasflowvelocitywithin 20%of thespecifiedvalueorofthechamberaveragewhenthechamberisempty.Forchamberswithadimensio
40、nofmore than0,1m,measurementpointsshallbeinaccordancewithA.3.2.Forchamberswithalldimensionsoflessthan 0,5m,aminimumoffivepointsshallbemeasuredatlocationsintheplaneofsampleexposure(perpendicularto theexpectedflowdirection)thatareequidistantfromeachotherandthewallsofthechamber.Afterallfiveormore datav
41、aluesarerecorded,allthemeasurementsshallberepeatedasecondtime.Whenthetwosetsof measurementshavebeenrecordedathirdcompletesetshallberecorded.Thearithmeticaverageofthe15or moremeasurementsshallbethechamberaverage,see6.5and6.6.8.Ifahotwireanemometerisusedforvelocity measurementstheseshallbemadeinaccord
42、ancewithISO9096,withtheexceptionthatsamplesitesshallbein accordancewithannexA. 5.2.3Asampleaccessportisdesirable.Thisshouldbedesignedsuchthatcontrolcouponscanberemovedor replacedwithoutinterruptingtheflowofgases.Corrosiontestchambercorrosionrateshavebeenshowntobea functionofthepresenceorabsenceoflig
43、ht(see4and5).Provisionshallbemadeforcontrollingthetest illuminationinaccordancewithatestspecification. 5.2.4ExamplesoftestchambersystemsareshowninFigures1,2and3. Theyshallnotbeconsideredasexclusiveexamples. Key 1Workingvolume 2Exhaust 3Baffleswith1mmholeson1cmcentres 4Inlet 5Pollutant1 6Pollutant2 7
44、Pollutant3 8Otherpollutants 9Moistair 10Dryair Figure1Schematicflowthroughmixedflowinggas(MFG)testsystemISO4524-2:2000(E) 4 Key 1Workingvolume 2Testchamberinsert 3Exhaust 4Temperaturecontrolledchamber 5Gasmonitoringmeters 6Fans 7Mixedgas/humidifiedair blendingarea 8Mainflow 9Humiditysource 10Air 11F
45、lowmeters 12Nitrogen 13Permeationtubes 14Limitingorifices 15Mixingchamber Figure2Schematicverticalrecirculatingmixedflowinggas(MFG)testsystem Key 1Gasconcentrationmeasurement points 2Temperatureandhumidity measurement 3Gasvelocitymeasurement 4Testsampleregion 5Baffles 6Gasconcentrationanalysis 7Test
46、sampledatacollection 8Chamberexhaust 9Mixedgassupply 10Fans 11Airflowdirection 12Humiditysource 13Multiplegassources 14Make-upair 15Gasmixingmanifold 16Temperaturecontrolchamber 17Corrosivegaschamber Figure3Schematichorizontalrecirculatingmixedflowinggas(MFG)testsystemISO4524-2:2000(E)5 5.3 Gassuppl
47、ysystem 5.3.1 Descriptionandrequirements Thegassupplysystemconsistsoffivemainparts: asourceofclean,dry,filteredair; ahumiditysource; corrosivegassource(s); gasdeliverysystem; corrosivegasconcentrationmonitoringsystem(s). Totalsupplycapacityshallbesuchastomeetrequirementsforcontrolofgasconcentrations
48、Theminimum numberofvolumechangesisdeterminedbytherequirementthattheconcentrationofcorrosivegasesbe maintainedwithin 15%betweengasinletandoutlet.Thisisverifiedbymeasurementofthegasconcentrations nearthegasinletupstreamoftheusablechamberworkingvolumeandcomparingwithgasconcentrations measureddownstrea
49、moftheusablechamberworkingvolumejustpriortothechamberexhaust.Thesevalues shallbewithin 15%(see6.3).Alternativemethodsofdemonstratingcompliancewiththemaximumallowable concentrationgradientareacceptable.Normallyaconditionedchamberequilibrateswithinseveralhoursofsample loadingandstartofcorrosivegassupply.Timeslongerthan2hshallbereportedinthetestreport;seeclause7. AguidetoestimatingsupplyrequirementsisprovidedinannexB. 5.3.2 Clean,dry,filteredairsource Gasesothertha
