英文文献综述review article.ppt

ScientificLiteratureReadings,Name:杨永喜StudentID:15S008154Winter2015SchoolofMechatronicsEngineering,ScientificLiteratureReadings,TribologyofGraphene:AReview,Authors:OleksiyPenkov,Hae-JinKim,Hyun-JonKim,Dae-EunKim,ScientificLiteratureReadings,Abstract,Graphenehasreceivedsignificantattentionduetoitscombinationofremarkablemechanical,thermal,chemicalandelectricalproperties.Furthermore,duetoitssuperiorstrength,graphenehasgreatpotentialforuseasanultra-thinprotectivecoatingforvariousprecisioncomponents.Inthispaper,thelatestdevelopmentsintribologicalapplicationsofgraphene,theoreticalsimulationsofgraphenefrictionandpreparationmethodsarereviewed.Itisshownthatvariousgraphenecoatingscanbesuccessfullyusedtodecreasefrictionandwearinnano-,micro-andmacro-mechanicalapplications.However,theconditionsunderwhichgrapheneservesasaneffectiveprotectivecoatingdependsontheoperatingparameters.Acomprehensivereviewisprovidedwiththeaimtoassesssuchcharacteristicsofgraphene.,Background,Conclusion,ScientificLiteratureReadings,Tribologicalbehaviorplaysanimportantroleintheperformanceofultra-precisionmechanicalsystems.,ABriefReviewofTribology,ScientificLiteratureReadings,ABriefReviewofTribology,Andthewearresistancedeterminesthemechanicalandcommercialviabilityofthedevice.,ScientificLiteratureReadings,However,asaresultofsurfacetensioneffects,classicalmethodsforreducingfrictionwithlubricatingfluidscannotbeemployedinmicrosystems.,LimitationsofClassicalMethod,ScientificLiteratureReadings,Differenttypesofthincoatingssuchassoftmetals,organiccompoundssuchasself-assembledmonolayers,bi-layerandmultilayerhardcoatings,diamond-likecarbonfilmsandnanostructuredcoatingscanbeusedtoreducefrictionandwearinmicro-devices.Unfortunately,despitereportsofnumerousproposedcoatings,anoptimummethodforreducingthefrictionandwearofthesedeviceshasnotyetbeenidentified.,LimitationsofClassicalMethod,ScientificLiteratureReadings,NewBreakthroughofTribology,Thecombinationoftheremarkablemechanical,thermal,chemicalandelectricalpropertiesofgraphenesheetsandtheirrelativelylowproductioncostdistinguishthemfromothermaterialsusedfornano-electromechanicalapplications.Thus,grapheneisconsideredasapromisingmaterialforfutureapplicationsinnanoelectronicandminiaturizeddevices.,ScientificLiteratureReadings,NewBreakthroughofTribology,Furthermore,duetoitssuperiorstrength,graphenehasgreatpotentialforuseasanultra-thinprotectivecoatingforvariousprecisioncomponentsexposedtocontactstress.,ScientificLiteratureReadings,PreparationofGraphene,Amongthesetechniques,thechemicalvapordeposition(CVD)growthmethodappearstobethemostpromisingforlarge-scaleproductionofmono-orfew-layergraphenefilms.,SimulationsandPredictions,ScientificLiteratureReadings,Thesesimulationstudiesrelatedtothetribologicalcharacteristicsofgraphene,frictionwastheprimaryfocus.Theinfluenceofvariousparametersonfriction,suchasthenumberofgraphenelayers,normalforce,adhesionforceandslidingvelocity,wereinvestigated.Thepurposeoftheseworkswastoprovideinsightintothefrictionalmechanismofgraphene,andthesimulationscouldsufficientlyreproducetheexperimentallyobservedtrendsofgraphenefrictionalbehavior.Moreover,severalresultsthatcouldnotbeobservedbyexperimentalmethods,suchasthemotionofindividualatoms,wereobtainedfromsimulationswhichaidedinincreasingtheunderstandingregardingthefrictionalmechanismofgraphene.,ScientificLiteratureReadings,Conclusions,1.Thekeyfactorsthatwerefoundtoinfluencethefrictionandwearbehaviorsofgraphenewerenumberoflayers,depositionmethod,andsubstratematerial.,2.Despitetheultra-thinnatureofgraphenesheets,theywereeffectiveinreducingthefrictionandwearnotonlyundermicro-scalecontactloadsbutalsoinrelativelyhighloads.,3.Furthermore,thetypeofsubstrateneededtoproducethetribologicaladvantagesofgraphenewasnotlimitedtoextremelyflatandsmoothsurfaces.Graphenewasfoundtobeeffectiveevenonmetallicsubstrateswithtypicalsurfacetopography.,ScientificLiteratureReadings,FutureResearchDirection,Withthedevelopmentofmoreefficientgraphenedepositionmethodsoveralargearea,theuseofgrapheneintribologicalapplicationsisexpectedtogrowcontinuouslyinthefuture.,DepositionMethods,ScientificLiteratureReadings,Relationships,Iwilllearnandstudytribologyinthefuture.Thepapergivemeagu