ASTM B809-1995(2008) 用湿硫黄蒸气("硫黄华")作金属涂层中孔隙率测试的标准试验方法

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【英文标准名称】:StandardTestMethodforPorosityinMetallicCoatingsbyHumidSulfurVapor("Flowers-of-Sulfur")
【原文标准名称】:用湿硫黄蒸气("硫黄华")作金属涂层中孔隙率测试的标准试验方法
【标准号】:ASTMB809-1995(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:1995
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:B08.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:Copperalloyelectrodepositedcoatings;ElectrodepositedCucoatings;“Flowers-of-sulfur”;Metalliccoatings;Porosity--electrodeposited/metalliccoatings;Silver;Sulfur--metals/alloys;Tarnish
【摘要】:Amajoruseofthistestprocedureisfordeterminingcoatingquality.Porositytestsareindicationsofthecompletenessofprotectionorcoverageofferedbythecoatings,sincethecoatingsdescribedin1.2areintendedtobeprotectivewhenproperlyapplied.Theporositytestresultsarethereforeameasureofthedepositionprocesscontrol.Aparticularpurposeofthehumidsulfurvaportestisfordeterminingthequalityofunderplatesofnickelornickelalloyinthosefinishsystemsthathavethin,1.2x03BC;morless(50x03BC;in.orless)toplayersabovethenickel,sinceporosityintheunderplateusuallycontinuesintosuchtoplayers.Thehumidsulfurvaportestisoftenusedasanenvironmentaltesttosimulatemanyindoorhumidatmospheretarnishingandtarnishcreepageeffects.However,thechemistryandpropertiesofthesetarnishfilmsmaynotresemblethosefoundinotherserviceenvironments.Forsuchproductperformanceevaluations,thetestshouldonlybeusedincombinationwithotherperformanceevaluationtests,asspecifiedinthereferencingdocumentforthatproduct.Porositytestsdifferfromcorrosionandagingtests,sincethelatterareintendedtomeasurethechemicalinertnessofthecoating.Incontrast,inagoodporositytestprocedurethecorrosiveagentshouldnotattackthecoating.Itmustinstead,clean,depolarize,oractivatethesubstratemetalexposedbythepore,orboth,andattackitsufficientlytocausereactionproductstofilltheporetothesurfaceofthecoating.Thehumidsulfurtestishighlysensitive,andiscapableofdetectingvirtuallyallporositythatpenetratesdowntocopperorcopperalloys.Sincenickelisnotattackedbymoistsulfurvaporat100x00B0;Corless,thistestwillnotdetectporesorcracksinthetopcoatingifsuchporesorcracksdonotpenetratethroughthenickelunderplateoverlayingthecopper.Thelevelofporosityinthecoatingthatmaybetolerabledependsontheseverityoftheenvironmentthattheproductislikelytoencounterduringserviceorstorage.Also,thelocationoftheporesonthesurfaceisimportant.Iftheporesarefewinnumberorawayfromthesignificantsurfaces,theirpresencecanoftenbetolerated.Thepresenttestmethodcanbeusedonsamplesofvariousgeometries,suchascurvedsurfaces.Itcanalsobeusedforselectiveareacoatings,ifallowanceismadefortarnishcreepagefrombarecopperalloyareas.Thistestmethodisdestructiveinthatitrevealsthepresenceofporositybycontaminatingthesurfacewithtarnishfilms.Anypartsexposedtothistestmethodshouldnotbeplacedinservice.Therelationshipofporositylevelsrevealedbythistestmethodtoproductperformanceandservicelifemustbemadebytheuserofthetestthroughpracticalexperienceorbyjudgment.Thus,absenceofporosityinthecoatingmaybearequirementforsomeapplications,whileafewporesonthesignificantsurfacesmaybeacceptableforothers.1.1Thisstandardcoversequipmentandtestmethodsfordeterminingtheporosityofmetalliccoatings,wheretheporespenetratedowntoasilver,copper,orcopper-alloysubstrate.1.2Thistestmethodissuitableforcoatingsconsistingofsingleorcombinedlayersofanycoatingthatdoesnotsignificantlytarnishinareducedsulfuratmosphere,suchasgold,nickel,tin,tin-lead,andpalladium,ortheiralloys.1.3Thistestmethodisdesignedtodeterminewhethertheporositylevelislessthanorgreaterthansomevaluewhichbyexperienceisconsideredbytheusertobeacceptablefortheintendedapplication.1.4Recentreviewsofporositytestingandtestingmethodscanbefoundinthe......
【中国标准分类号】:A29
【国际标准分类号】:25_220_40
【页数】:5P.;A4
【正文语种】:英语