astm d968-15 standard test methods for abrasion resistance of organic coatings by falling abrasive

1、Designation:D968?15StardTestMethodsfAbrasionResistanceofganicCoatingsbyFallingAbrasive1ThisstardisissuedunderthefixeddesignationD968thenumberimmediatelyfollowingthedesignationindicatestheyearofiginaladoptioninthecaseofre

2、visiontheyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperepsilon()indicatesaneditialchangesincethelastrevisionreapproval.ThisstardhasbeenapprovedfusebyagenciesoftheU.S.DepartmentofDefense.1.

3、Scope1.1Thesetestmethodscoverthedeterminationoftheresistanceofganiccoatingstoabrasionproducedbyabrasivefallingontocoatingsappliedtoaplanerigidsurfacesuchasametalglasspanel.1.2Twotestmethodsbasedondifferentabrasivesarecov

4、eredasfollows:SectionsMethodA—FallingSAbrasionTest6–13MethodB—FallingSiliconCarbideAbrasionTest14–211.3Thesemethodsshouldberestrictedtotestinginonlyonelabatywhennumericalvaluesareusedbecauseoftheporeproducibilityofthemet

5、hods(see13.1.221.1.2).Interlabatyagreementisimprovedsignificantlywhenrankingisusedinplaceofnumericalvalues.1.4ThevaluesstatedinSIunitsaretoberegardedasthestard.Thevaluesgiveninparenthesesarefinfmationonly.1.5Thisstarddoe

6、snotpurpttoaddressthesafetyconcernsifanyassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstardtoestablishappropriatesafetyhealthpracticesdeterminetheapplicabilityofregulatylimitationspritouse.2.ReferencedDocument

7、s2.1ASTMStards:2D823PracticesfProducingFilmsofUnifmThicknessofPaintVarnishRelatedProductsonTestPanelsD1005TestMethodfMeasurementofDryFilmThicknessofganicCoatingsUsingMicrometersD7091PracticefNondestructiveMeasurementofDr

8、yFilmThicknessofNonmagicCoatingsAppliedtoFerrousMetalsNonmagicNonconductiveCoatingsAppliedtoNonFerrousMetalsE11SpecificationfWovenWireTestSieveClothTestSieves2.2OtherStards:ANSIB74.12SpecificationsftheSizeofAbrasiveGrain

9、—GrindingWheelsPolishingGeneralIndustrialUses3FEPAStard422:2006GrainsofFusedAluminumOxideSiliconCarbideotherAbrasiveMaterialsfBondedAbrasivesfGeneralApplications—MicrogritsF230toF200043.Terminology3.1DefinitionsofTermsSp

10、ecifictoThisStard:3.1.1abrasionresistancen—theamountofabrasiverequiredtowearthroughaunitfilmthicknessofthecoating.4.SummaryofTestMethod4.1Abrasiveisallowedtofallfromaspecifiedheightthroughaguidetubeontoacoatedpaneluntilt

11、hesubstratebecomesvisible.Theamountofabrasiveperunitfilmthicknessisreptedastheabrasionresistanceofthecoatingonthepanel.Silicassiliconcarbidemaybeusedasspecified.5.SignificanceUse5.1Silicasproducesaslowerrateofabrasionfga

12、niccoatingsthanthatprovidedbysiliconcarbide.Fsometypesofcoatingsitmayalsoprovidegreaterdifferentiation.5.2Theabrasionresistancescalesproducedbythetwomethodsdifferbutthemethodsprovideapproximatelythesamerankingsofcoatings

13、fabrasionresistance.1ThesetestmethodsareunderthejurisdictionofASTMCommitteeD01onPaintRelatedCoatingsMaterialsApplicationsarethedirectresponsibilityofSubcommitteeD01.23onPhysicalPropertiesofAppliedPaintFilms.Currenteditio

14、napprovedJune12015.PublishedJune2015.iginallyapprovedin1948.Lastpreviouseditionapprovedin2010asD968–05(2010).DOI:10.1520D096815.2FreferencedASTMstardsvisittheASTMwebsitewww.astm.gcontactASTMCustomerServiceat.FAnnualBooko

15、fASTMStardsvolumeinfmationrefertothestard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanNationalStardsInstitute(ANSI)25W.43rdSt.4thFloNewYkNY10036:www.ansi.g.4AvailablefromFederationofEuropeanProducersofAbra

16、sives(FEPA)20av.ReilleParisF75014www.fepaabrasives.g.Copyright?ASTMInternational100BarrHarbDrivePOBoxC700WestConshohockenPA194282959.UnitedStates1s(2000610mLisaconvenientamount)determinethetimeofefflux.Therateofflowshall

17、be2Lofsin21to23.5s.8.2Secureatrialpanelinthetestingpositionasdescribedin6.1introducethesinincrementsuntilaspot4mm(5?32in.)indiameteriswnthroughtothebasematerial.Theoverallabradedareashallbeellipticalinshapeabout25mm(1in.

18、)inwidth30mm(11?4in.)inlength.Thecenteroftheareaofmaximumabrasionshallbeonthecenterlinethroughthelongeraxisoftheabradedpatternwithin14to17mm(9?16to11?16in.)ofthetopedge.Slightfinaladjustmentoftheinstrumentmayberequiredto

19、centertheabrasionspotinthepattern.8.3Afinalcheckonalignmentismadebydeterminingtheamountofsthatpassesthrougha4mm(5?32in.)holeinametalpanelplaceddirectlyunderthetube.Placeacontainerundertheholeinthepanelallowaweighedamount

20、ofstopassthroughthetubeontothepanel.Weightheamountofsthatpassedthroughtheholeintothecontainer.Theapparatuscanbeconsideredtobeincalibrationiftheamountofsthatpassedthroughtheholeis90to93%oftheamountofsthatimpingedonthepane

21、l.9.Conditioning9.1Unlessotherwiseagreeduponbetweenpurchasersellerconditionthecoatedtestpanelsfatleast24hat2362C5065%relativehuity.Conductthetestinthesameenvironmentimmediatelyonremovaltherefrom.10.Procedure10.1Oneachcoa

22、tedpanelmarkthreecircularareaseachapproximately25mm(1in.)indiametersoarrangedthateachcanbeproperlypositionedinthepanelsupptoftheabrasiontester.MeasurethethicknessofthecoatingbyTestMethodsD1005D7091inatleastthreelocations

23、ineacharea.Recdthemeanofeachsetofmeasurementsasthethicknessofthecoatingovertherespectivearea.10.2Afterconditioningsecurethecoatedpanelinthetesterasdescribedin6.1.Adjustthepanelsothatoneofthemarkedareaswillbecenteredunder

24、theguidetube.10.3Pourstardsmeasuredvolumetricallyintothefunnel.Withdrawthegateallowthestoflowthroughtheguidetubeimpingeonthecoatedpanel.Collectthesinacontainerlocatedatthebottomofthetester.Repeatthisoperationuntila4mm(5?

25、32in.)diameterareaofthecoatinghaswnthroughtothesubstrate.Aconvenientincrementofstoemployduringthetestis2000610mL.Astheendpointisapproachedincrementsof20062mLmaybeintroducedintothefunnel.NOTE5—Whenthegateiswithdrawnfromth

26、eguidetubemakecertainthatacollarcoverstheslitopeninginthetube.10.4Abradeeachoftheremainingmarkedoffareasofthecoatedpanelasoutlinedin10.2.NOTE6—Checkthealignmentoftheguidetubeatfrequentintervalstoensurethattheconcentrated

27、innerceofthesstreamisfallinginthecenteroftheflow.NOTE7—After25passesthroughtheapparatusresievetheswithaNo.30sievetoremovefines.Replacethesafter50passes.10.5Repeat10.1–10.4onatleastoneadditionalpanelcoatedwiththematerialu

28、ndertest.11.Calculation11.1FeachareaofthecoatedpaneltestedcalculatetheabrasionresistanceAinlitrespermilfromthefollowingequation:Avolume5VT(1)where:V=volumeofabrasiveusedL(toonedecimalplace)T=thicknessofcoatingmils(tooned

29、ecimalplace).11.2Calculatethemeanoftheabrasionresistancevaluesobtainedfdifferentareasofthecoatedpanelthemeanvalueofthereplicatepanels.12.Rept12.1Reptthefollowinginfmationfeachcoatedpaneltested:12.1.1Temperaturehuitydurin

30、gcuringatthetimeoftesting12.1.2Typesourceofabrasive12.1.3Litresofabrasiveusedfeachareatested12.1.4Coatingthicknessinmilsfeachareatested12.1.5Abrasionresistancevaluesfeachareatested12.1.6Meanabrasionresistancefeachcoatedp

31、aneltested12.1.7Meanabrasionresistancerangeofthereplicatecoatedpanels.13.Precision613.1Onthebasisofaninterlabatytestofthistestmethodinwhichthreelabatiestestedfourtypesofcoatingsdifferingintheirabrasionresistancethewithin

32、labatycoefficientofvariationwasfoundtobe9%with22dfthebetweenlabatiescoefficientofvariation35%with7df.Basedonthesecoefficientsthefollowingcriteriashouldbeusedfjudgingtheacceptabilityofresultsatthe95%confidencelevel.13.1.1

33、Repeatability—Tworesultseachthemeanofthreerunsobtainedbythesameoperatshouldbeconsideredsuspectiftheydifferbymethan25%oftheirmeanvalue.13.1.2Reproducibility—Tworesultseachthemeanofthreerunsobtainedbyoperatsindifferentlaba

34、tiesshouldbeconsideredsuspectiftheydifferbymethan118%oftheirmeanvalue.NOTE8—Thereproducibilityofthistestisimprovedsubstantiallywhenrankingsofthecoatingsbymagnitudeofabrasionresistanceareused.Intheinterlabatytestfevaluati

35、ngprecisionalllabatiesrankedthecoatingsinthesameder.13.2Bias—Atthetimeofthestudytherewasnoacceptedreferencematerialsuitablefdeterminingbiasfthistestmethodtherefenostatementonbiasisbeingmade.6SupptingdatahavebeenfiledatAS