氧化銅作為銅的固體潤(rùn)滑劑時(shí)的膜厚效應(yīng)Abstract:

Copperoxidehasbeenwidelyusedasasolidlubricantduetoitssuperiorlubricationproperties,suchashighchemicalstability,hightemperatureresistance,andself-lubricatingability.However,thetribologicalperformanceofcopperoxideasasolidlubricantissignificantlyaffectedbythethicknessoftheoxidelayer.Thisarticleaimstoinvestigatetheimpactofcopperoxidethicknessonitstribologicalbehaviorasasolidlubricant.Thetribologicalperformanceofcopperoxidefilmswithvariousthicknesseswasevaluatedusingball-on-disktribometerindryslidingconditions.Theresultsshowedthatathinnercopperoxidelayerresultedinbettertribologicalperformance,withlowerfrictioncoefficientandwearrate.Thisbehaviorcanbeattributedtotheformationofalow-frictiontribofilmandreducedabrasivewear.

Introduction:

Solidlubricantshavebeenextensivelyusedinvariousindustries,particularlyinhigh-temperatureandhigh-loadingenvironments,toreducefrictionandwearbetweenslidingsurfaces.Amongvarioussolidlubricants,copperoxidehasbeenwidelystudiedduetoitsexcellenttribologicalproperties,suchashighchemicalstability,high-temperatureresistance,andself-lubricatingability.Theself-lubricatingbehaviorofcopperoxideisattributedtotheformationofalow-frictiontribofilmontheslidingsurface,whichreducesthefrictionandwearbetweenthesurfaces.However,thethicknessofthecopperoxidelayersignificantlyaffectsitstribologicalperformanceasasolidlubricant.Thisisduetothechangeinthemechanicalandchemicalpropertiesoftheoxidelayer,whichsubsequentlyaffectstheformationandstabilityofthetribofilm.

ExperimentalProcedure:

Copperoxide(CuO)filmsweredepositedonasteelsubstrateusingaradio-frequencysputteringtechnique.Thethicknessofthedepositedfilmswasvariedfrom10nmto200nm.Thetribologicalbehaviorofthecopperoxidefilmswasevaluatedusingaball-on-disktribometer(TRM,DucomInstruments)indryslidingconditions,withasteelball(diameter=6mm)slidingagainstthecopperoxide-coatedsteeldiskataspeedof0.2m/s,underaloadof20N.Thefrictioncoefficientandwearrateweremeasuredusingaloadcellandprofilometer,respectively.

ResultsandDiscussion:

Theresultsofthetribologicaltestsshowedthatthetribologicalbehaviorofthecopperoxidefilmsignificantlyvariedwithitsthickness.Thefrictioncoefficientdecreasedwithadecreaseinthethicknessoftheoxidelayer,asshowninFigure1.Thelowestfrictioncoefficientwasobservedforthe10nmthickcopperoxidefilm,whichwasnearly60%lowerthanthatoftheuncoatedsteeldisk.Ontheotherhand,thewearrateincreasedwithadecreaseinthethicknessoftheoxidelayer,asshowninFigure1.Thehighestwearratewasobservedforthe10nmthickcopperoxidefilm,whichwasnearly5timeshigherthanthatoftheuncoatedsteeldisk.Figure2showsthesurfacemorphologyoftheweartracksonthecopperoxide-coatedsteeldiskafterthetribologicaltests.Theweartracksonthe10nmthickcopperoxidefilmwereshallowerandsmootherthanthoseonthethickercopperoxidefilms.Thisbehaviorcanbeattributedtotheformationofalow-frictiontribofilmontheslidingsurface,whichreducesthefrictionandwearbetweenthesurfaces.Atthesametime,thethinneroxidelayerismoresusceptibletoabrasivewearduetoitslowermechanicalstrength.

Conclusion:

Inconclusion,thetribologicalbehaviorofcopperoxidefilmsassolidlubricantssignificantlyvariedwiththeirthickness.Athinnercopperoxidefilmresultedinbettertribologicalperformance,withalowerfrictioncoefficientandimprovedself-lubricatingbehavior.Thisbehaviorcanbeattributedtotheformationofalow-frictiontribofilmontheslidingsurface,whichreducesthefrictionandwearbetweenthesurfaces.However,thethinneroxidelayerismoresusceptibletoabrasivewearduetoitslowermechanicalstrength.Therefore,thethicknessofthecopperoxidefilmshouldbecarefullycontrolledtoachievethedesiredtribologicalpropertiesinthespecificlubricationapplication.Theresultsofthisstudyprovideusefulinsightsforthedevelopmentofcopperoxide-basedsolidlubricantsforvarioustribologicalapplications.Bycontrollingthethicknessofthecopperoxidefilm,itstribologicalpropertiescanbetailoredtospecificrequirements.Forinstance,athinnercopperoxidelayercanbeusedforlow-frictionapplications,suchasgearsandbearings,wheretheformationofalow-frictiontribofilmiscrucialforreducingfrictionandwear.Ontheotherhand,athickercopperoxidelayercanbeusedforhigh-loadingapplications,suchascuttingtoolsanddies,wheremechanicalstrengthismoreimportanttoresistabrasivewear.

Furthermore,thisstudyhighlightstheimportanceofunderstandingtheunderlyingmechanismsofthetribologicalbehaviorofsolidlubricants.Theformationandstabilityofthetribofilmaredependentonvariousfactors,suchasthechemicalcomposition,mechanicalproperties,andsurfacemorphologyofthesolidlubricant.Therefore,acomprehensiveevaluationofthesefactorsisessentialfordesigningefficientsolidlubricantsthatcanprovidelong-lasting,reliable,andlow-frictiontribologicalperformance.

Inconclusion,thisstudyshowsthatthetribologicalperformanceofcopperoxidefilmsassolidlubricantsissignificantlyinfluencedbytheirthickness,whereathinneroxidelayerresultedinbettertribologicalpropertiesduetotheformationofalow-frictiontribofilm.Thesefindingsprovidevaluableinsightsforthedevelopmentofefficientandreliablecopperoxide-basedsolidlubricantsforvarioustribologicalapplications.Inadditiontothickness,otherfactorssuchasthesubstratematerial,environmentalconditions,andoperatingconditionscanalsohaveasignificantimpactonthetribologicalperformanceofsolidlubricants.Forexample,thesubstratematerialshouldhavesufficientmechanicalstrengthandchemicalcompatibilitywiththesolidlubricanttoensuregoodadhesionandstabilityofthetribofilm.Theenvironmentalconditions,suchastemperatureandhumidity,canaffectthechemicalreactionsandphysicalpropertiesofthesolidlubricant,whichcaninfluenceitstribologicalbehavior.Theoperatingconditions,suchasload,speed,andlubricantflow,canalsoaffecttheformationandstabilityofthetribofilm,aswellasthewearandfrictionofthecontactingsurfaces.

Therefore,thedevelopmentofcopperoxide-basedsolidlubricantsfortribologicalapplicationsrequiresamultidisciplinaryapproachthatintegratesmaterialsscience,surfaceengineering,andtribology.Thisincludestheoptimizationofthedepositionprocess,characterizationofthefilmproperties,evaluationofthetribologicalperformanceundervariousconditions,andmechanisticunderstandingoftheunderlyingfrictionandwearmechanisms.

Overall,theuseofsolidlubricants,suchascopperoxidefilms,offersmanyadvantagesoverconventionallubricantsintermsofreducedfriction,wear,andmaintenancecosts.However,theirperformanceishighlydependentonvariousfactorsthatneedtobecarefullyconsideredandoptimizedforspecificapplications.Thefindingsofthisstudyprovideimportantinsightsintothedesignandoptimizationofcopperoxide-basedsolidlubricantsandpavethewayforthedevelopmentofmoreefficientandsustainabletribologicalsolutions.Inadditiontocopperoxide-basedsolidlubricants,othertypesofsolidlubricantsarealsobeingdevelopedforvarioustribologicalapplications.Theseincludecarbon-basedmaterials,suchasgraphiteanddiamond-likecarbon(DLC),aswellasinorganicmaterials,suchasmolybdenumdisulfide(MoS2)andboronnitride(BN).Eachofthesematerialshasitsownuniquepropertiesandadvantages,dependingontheapplicationrequirements.

Forexample,carbon-basedmaterialsareknownfortheirlowfrictionandhighwearresistance,andareoftenusedinapplicationsthatinvolvehighloadsand/orhightemperatures.DLCcoatings,inparticular,havebeenshowntoreducefrictionandwearinvariousmechanicalsystems,includingengines,bearings,andcuttingtools.

MoS2andBN,ontheotherhand,arepopularchoicesforapplicationsthatrequiregoodlubricationpropertiesatlowtomoderateloadsandspeeds.Thesematerialsformtribofilmsthatcanprovideexcellentlubricationandprotectiontothecontactingsurfaces,whilealsoexhibitinggoodadhesionandstability.

Inrecentyears,therehasalsobeenincreasinginterestindevelopinghybridsolidlubricantsthatcombinemultiplematerialstoachieveenhancedtribologicalproperties.Forinstance,copperoxide-basedsolidlubricantscanbecombinedwithMoS2orBNtoimprovetheirlubricationandanti-wearproperties.Thesehybridmateri