ASTM B866-1995(2008) 用聚硫化物浸入法测试金属涂层中总疵点和机械损坏的标准试验方法

作者:标准资料网 时间:2024-05-18 19:06:26  浏览:8447   来源:标准资料网

【英文标准名称】:StandardTestMethodforGrossDefectsandMechanicalDamageinMetallicCoatingsbyPolysulfideImmersion
【原文标准名称】:用聚硫化物浸入法测试金属涂层中总疵点和机械损坏的标准试验方法
【标准号】:ASTMB866-1995(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】:electrodeposits;grossdefects;mechanicaldamage;metalliccoatings;polysulfideimmersion;porositytesting;wear-through;Defects--metals/alloys;Electrodepositedcoatings;Grossdefects;Mechanicaldamage;Metalliccoatings;Polysulfideimmersio
【摘要】:Thepurposeofthealkalinepolysulfideimmersiontestistodeterminethepresenceofmechanicaldamage,wear-through,andothergrossdefectsinthecoating.Mostmetalliccoatingsareintendedtobeprotectiveandthepresenceofgrossdefectsindicatesaseriousreductionofsuchprotection.Theprotectionaffordedbywellappliedcoatingsmaybediminishedbyimproperhandlingfollowingplatingorasaresultofwearormechanicaldamageduringtestingorwhileinservice.Thealkalinepolysulfidetestservestoindicateifthedamagehasextendeddowntothecopperorcopperalloybasismetalsinceitwillnotdetectexposednickelunderplate.ThealkalinepolysulfidetesthasbeenspecifiedinseveralASTMspecificationsfortin-platedcoatings,namelySpecificationsB246andB545.Thistestcouldalsobeusedtodetectgrossdefectsandmechanicaldamageinothermetalliccoatings,suchastin-nickelalloy(SpecificationB605),nickel(SpecificationB689),gold(SpecificationB488),palladium(SpecificationB679),andautocatalyticnickel-phosphorouscoatings(SpecificationB733).Thistestdetectsmechanicaldamagethatexposescopperunderplateandcopperbasismetal.Suchdamagemayoccurinanypost-platingoperationoreventowardstheendoftheplatingoperation.Itismostoftenseentooccurinproductassemblyoperations.Ifproperlyperformed,thistestwillalsodetectwear-through,providedthewear-throughreachesacopperorcopper-alloylayer.Manytypesofgrossdefectsaretoosmalltobeseen,exceptatmagnificationssohigh(asinSEM)thatarealisticassessmentofthemeasurementareacannotbeeasilymade.Otherdefects,suchasmanytypesofwear-through,provideinsufficientcontrastwiththecoatingsurface.Grossdefectstests(aswithporositytests)are,therefore,usedtomagnifythedefectsitesbyproducingvisiblereactionproductsinandaroundthedefects.Thepolysulfidesolutionwillreactwithcopperandcopperalloystoproduceadarkbrownorblackstain(thedefectindications)atthesiteofthedefect.Silveralsoturnsblackunderthesameconditions.Thetestsolutionwillnotreactwithnickelandisonlyusefulwhenthepresenceorabsenceofcopperexposureisaspecificrequirement.Thepolysulfideimmersiontestisrelativelyinsensitivetothepresenceofsmallpores.Itshallnotbeusedasageneralporositytest.(TestMethodB809shouldbeusedinstead.)Theextentandlocationofthegrossdefectsormechanicaldamage(revealedbythistest)mayormaynotbedetrimentaltoproductperformanceorservicelife.Suchdeterminationsshallbemadebytheuserofthetestthroughpracticalexperienceorjudgment.Thepresenttestcanbeusedonsamplesofvariousgeometries,suchascurvedsurfaces.Itcanalsobeusedforselectiveareacoatingifallowanceismadefortarnishcreepagefrombarecopperalloyareas.Thistestisdestructiveinthatitrevealsthepresenceofgrossdefectsbycontaminatingthesurfacewithreaction-productfilms.Anypartsexposedtothistestshallnotbeplacedinservice.However,thedefectindicationsonthesamplesurfacesthatresultfromthistestarestable;samplesmayberetainedforreferencepurposes.Thistestisneitherrecommendedforpredictionsofproductperformancenorisitintendedtosimulatefieldfailuremechanisms.Forsuchproductperformanceevaluations,anenvironmentaltestthatisknowntosimulateactualfailuremechanismsshouldbeused.1.1Thistestmethodcoversequipmentandmethodsfordetectinggrossdefectsandmechanicaldamage(includingwear-through)inmetalliccoatingswherethebreaksinthecoati......
【中国标准分类号】:A29
【国际标准分类号】:25_220_40
【页数】:4P.;A4
【正文语种】:英语