Archard磨损模型英文原文

ContactandRubbingofFlatSurfacesJ.F.ArchardCitation:J.Appl.Phys.24,981(1953);doi:10.1063/1.1721448Viewonline::::::://jap.aip.org/about/rights_and_permissionsJOURNALOFAPPLIEDPHYSICSVOLUME24.NUMBER8A{'(;{·ST.1953ContactandRubbingofFlatSurfacesJ.F.AR.CHARJ)ResearchLaboratory,AssociatedElectricalIndustriesLimited,Aldermaston,Berkshire,England(ReceivedJanuary8,1953)Theinterpretationofcertainphenomenaoccuringatnominallyflatsurfacesinstationaryorslidingcontactisdependentontheassumeddistributionoftherealareaofcontactbetweenthesurfaces.Sincethereislittledirectevidenceonwhichtobaseanestimateofthisdistribution,theapproachusedistosetupasimplemodelandcomparethededucedtheory(e.g.,thededuceddependenceoftheexperimentalobservablesontheload)withtheexperimentalevidence.Themainconclusionsareasfollows.(a)Theelectricalcontactresistancedependsonthemodelusedtorepresentthesurfaces;themostrealisticmodelisoneinwhichincreasingtheloadincreasesboththenumberandsizeofthecontactareas.(b)Ingeneral,mechanicalwearshouldalsodependonthemodel.However,inwearexperimentsshowingthesimplestbehavior,thewearrateisproportionaltotheload,andtheseresultscanbeexplainedbyassumingremovaloflumpsatcontactareasformedbyplasticdeformation;moreover,thisparticulardeductionisindependentoftheassumedmodel.Thissuggeststhatabasicassumptionofprevioustheories,thatincreasingtheloadincreasesthenumberofcontactswithoutaffectingtheiraveragesize,isredundant.I.GENERALINTRODUCTIONWHENtwonominallymatingsurfacesarebroughttogether,theytouchatthetipsofthehigherasperitiesandthetotalareaofintimatecontactisdeterminedbythedeformationofthematerialintheseregionsundertheappliedload.Therealareaofcontact,whichis,ingeneral,asmallpartoftheapparentareaofcontact,thereforecomprisesseveralindividualareas,thenumber,size,anddistanceofseparationofwhichwillinfluencetheresultsofcertaintypesofexperiment.Forexample,ithasbeenrecognizedthatthesefactorswillaffectthecontactresistanceorthelocaltemperaturescausedbyfrictionalheatingduringsliding(BowdenandTaborl;Holm2);*alsothechar­acterandmagnitudeofthetransferofmaterialbetweenrubbingsurfacesandtheirwearratemayshowasimilardependence.Inmanyexperiments,inordertoovercometheuncertaintiesastothedistributionoftherealareaofcontact,crossedcylindersoraspherepressedagainstaflatareused.Itisthenassumedthatthetotalareaofcontactisconfinedtoasinglecircularareaandthattheexperimentrepresentstheconditionsoccurringattheindividualcontactsbetweenthematingsurfaces.However,inordertoapplytheresultsofsuchexper­imentstothemoregeneralcase,itisnecessarytomakesomeassumptionsaboutthedistributionoftherealareasofcontactandthentodeducetheeffectofthisonthebehaviorofmatingsurfaces.Thispaperrepresentsanattempttotackletheproblem.Thereislittledirectevidenceonwhichtobaseanyestimateofthesizesanddistributionoftheindividualareasinvolvedinthecontactofmatingsurfaces.Therefore,theapproachusedistosetupasimplemodeltorepresentthesurfacesandtocomparethetheoreticaldeductionswiththeresultsofexperiments.Themultiple1F.P.BowdenandD.Tabor,TheFrictionandLubricationojSolids(OxfordUniversityPress,London,1950).2R.Holm,ElectricalContacts(H.Gerbers,Stockholm,1946).*ThesetworeferenceswillbereferredtothroughoutthispaperasB.T.andE.C.H.,respectively.contactconditionwillbeconsideredintermsofthecontactoftwonominallyflatsurfaces.Atthelightestloads,itisassumedthattheytouchoverthreesmallareas.Astheloadisincreased,theseareasincreaseinsize;alsosomeoftheasperities,hithertoseparated,approachandtouchtoformnewareasofcontact.Thus,itisassumedthatanincreaseintheloadincreasesboththenumberandsizeofthecontactareas;atthesametimeitautomaticallyfollowsthatthesecontactareashaveasizedistribution.Usingamodelwhichincorporatesthesefeatures,therelationshipsbetweentheappliedloadandthecontactareaorelectricalconductancehavebeendeducedandarecomparedwiththecorrespondingexpressionsforthesinglecontactcondition.Makingfurthersimpleassumptionsastothenatureoftheslidingprocess,simplelawsofmechanicalwearhavebeendeduced.Thesetheoreticalconclusionsarediscussedinthelightoftheexperimentalevidence.II.CONTACTAREAANDCONDUCTANCE1.IntroductionTheradiusaofthecircularareaofcontactformedwhenasphereofradiusRispressedagainstaflatsurfaceunderaloadPisgivenbyta=l'l{!PR(~l+~)r,(1)whenthedeformationiselastic,EIandE2beingtheYoung'smoduliofthematerialsofthecontactingmembers,and(2)whenthedeformationisplastic,pmbeingtheflowpressure(assumedconstant)ofthedeformablemember.TheconductanceGofsuchacontactisgivenbyG=2au,(3)tFordetailsofEq.(1)to(4)seeB.T.andE.C.H.981Downloaded13Nov2011to166.111.54.208.RedistributionsubjecttoAIPlicenseorcopyright;see