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关于材料表面微纳米颗粒对材料功能性影响的判定新方法克拉玛依

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关于材料表面微纳米颗粒对材料功能性影响的判定新方法

关于材料表面微纳米颗粒对材料功能性影响的判定新方法 2011年12月04日 来源: ABSTRACT《br》《br》Commonmaterialproperties(e.g.hardness,tensilemodulusandstrength,poisson?sratio)arewellknown.Ontheotherhand,propertiesofthinlayersandmicrovoluminacandiffersignificantfromthosedata,inparticularformicro/nano-particlesystems.AFMandFFMmethodsworkwithexcellentlateral,topographicandforceresolutionbutoftendonotprovidetesting-situationsclosetopracticalapplications,e.g.highpressureflatcontactwithinmicrowearandmicrofrictioninvestigations.Optimizationoffriction/wear-propertiesofmultimicro-areacontactespeciallyofrelevanceoncurvedandtopographicallystructuredsurfacesneedaccesstomeasurementtechnique,thatcoversthegapbetweenmicroandnanoscale.TheresultspresentedherearedonewiththeUST(UniversalSurfaceTester)todeterminetheinfluenceofincorporationofmicro/nano-particlesandtheirdistributiononmicroechanicalandfunctionalpropertiesofpolymermaterialsclosetothesurface.《br》1.COMPOSITEMATERIALS《br》Duringthelastdecadetherewasanincreaseintheusageofcompositematerialsevenforconsumerproducts.Themainreasonforthisisthebroadrangeofmechanicalpropertieswhichcanbereached.Tailor-madepropertiesarepossiblefornearlyeachapplication.Inalotofcasescarbonisusedastheappropriatefiller.Carbonblackisusedforrubberwhereascarbonfibresareusedforoptimizingmechanicalpropertiesliketheyoung’smodulus,tearstrengthandwearresistance.Eventhedynamicalpropertiesofcomposite《br》materialsarebetter.《br》2.NANO-ANDMICROCOMPOSITEMATERIALS《br》Anotherincreaseinpropertiesispossiblebyusageofmicro-ornanoparticles.Forexamplecarbonshowsawholefamilyofunusualsp?-hybridizedmodificationslikefullerenes[1]andcarbonnanotubes[2].Carbonnanotubesshowextremelyhighstabilityalsoathightemperatures.Alotofinterestingapplicationsarepossiblebyusingnanotubesforreinforcement[3].《br》Table1showsthepropertiesoftypicalfibresincomparisontocarbonnanotubes[4].《br》“Table1.TypicalPropertiesoffibres.”《br》Propertycarbonfibrecarbonnanotube《br》Young’sModulus(GPa)2301000《br》Tearstrength(GPa)430《br》Length/Diameterratio《100》1000《br》3.SURFACEPROPERTIES《br》Asmentionedmicro-andnanoparticlesareusedforreinforcementofthematerial.Inalotofcasesthebulkpropertieslikemodulusarenotsoimportant.Functionalsurfacepropertieslikewearorscratchresistanceareofmoreimportanceinsomeapplications.Besidesthetechnicaladvantagethereisanimportantreasonfortheproducertoconcentrateonsurfaceproperties.《br》Theappearanceofasurfaceletacustomerjudgethevalueoftheproduct.Thereforeitisnecessarytoimprovethesurfaceresistanceovertime.Daimler-Chryslerisusinganewdevelopednanopainttoimprovescratchresistanceoftheirautomobiles[5].Thenew40μmthicklacquerfinishincludesceramicparticleswithadiameterof20nm.Figure1showstheeffectofnanofillersonthescratchbehaviourofpolymers.《br》《br》《br》Fig.1.Scratchonanepoxywithandwithoutnanofillers[6].《br》Theuseoflacquerorspecialcoatingsimprovethesurfacepropertieslikeelasticity,hardness,frictionwithoutusingabigamountofmaterial.environmentalresistanceandchemomechanicalresistancearealsoimproved.《br》《br》4.MICROSTRUCTUREANALYSIS(MISTAN?)《br》AllmeasurementsaredonewithanUniversalSurfaceTester(UST?)whichisanewandpatentedmeasuringandtestingdeviceforcontinuouslydeterminingthedeformationbehaviourofamaterialinaregionnearitssurface.TheUSTyieldsmeasuredvaluesof:permanent,plastic,elastic,viscoelasticandtotaldeformation,microhardness,hardnessstructure,abrasionandscratchresistance,creepingandrelaxation,roughness,hapticandsoftness,cuttingandpiercingresistance,thicknessandstructureoflayersandofmicrofriction.Allthisvaluesareobtainedwithahighprecisionwithonlyonesingleinstrument.Whereasexistingprocedures,e.g.hardnessmeasurements,canonlycarryoutpointbypointmeasurements,theUSTrecordscontinuouslythematerialpropertiesalongthesurface.Ifrequired,theroughnessparametersaredeterminedfromthesurfaceprofilesaccordingtotheDINorISOstandardsdependingontheusedtipgeometryand&

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