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幾種納米微粒作為鋰基脂添加劑對(duì)鋼-鋼摩擦副摩擦磨損性能的影響研究Abstract
Theeffectofseveraltypesofnanometerparticlesaslithiumgreaseadditivesonfrictionandwearperformanceofsteel-steelfrictionpairwasinvestigated.Theresultsshowedthattheadditionofnanometerparticlescouldeffectivelyimprovethefrictionandwearpropertiesoflithiumgrease.Amongthem,theadditionof0.5%Al_2O_3particlescouldachievethebesteffect,reducingfrictioncoefficientby25.3%andwearrateby59.2%.Theadditionofothernanometerparticles,suchasSiO_2,TiO_2,andZnO,alsohadcertaineffectsonimprovingthefrictionandwearpropertiesoflithiumgrease.Themechanismanalysisshowedthatthenano-particlesformedaprotectivefilmonthefrictionsurfaceofsteel,reducingdirectcontactbetweenthefrictionpairsandimprovingtheenergytransferefficiency.Thisstudyprovidesatheoreticalbasisforthedevelopmentandapplicationoflithiumgreaseadditiveswithgoodfrictionandwearproperties.
Keywords:nanometerparticles;lithiumgrease;frictionandwear;steel-steelfrictionpair
Introduction
Inrecentyears,withthedevelopmentofmechanicalequipment,therequirementforhighwear-resistantmaterialsandlubricantshasbecomeincreasinglyurgent.Asawidelyusedlubricatingmaterial,lithiumgreasehasgoodperformanceinmechanicallubricationduetoitsgoodadhesion,waterresistance,andoxidationresistance[1].However,thefrictionandwearpropertiesoflithiumgreasestillneedtobeimproved,especiallyinthesteel-steelfrictionpair,whichiswidelyusedinengineeringapplications[2].Therefore,itisnecessarytoexplorenewmethodstoimprovethefrictionandwearpropertiesoflithiumgreaseinthesteel-steelfrictionpair.
Nanometerparticleshaveuniquephysicalandchemicalproperties,whichhavearousedgreatinterestinmanyresearchfields.Inrecentyears,nanometerparticleshavebeenusedaslubricantadditivestoimprovethefrictionandwearpropertiesoflubricants.Theadditionofnanometerparticlescanformaprotectivefilmonthefrictionsurface,reducingdirectcontactbetweenthefrictionpairsandimprovingtheenergytransferefficiency,thuseffectivelyimprovingthefrictionandwearpropertiesoflubricants[3].
Inthisstudy,severaltypesofnanometerparticleswereaddedtolithiumgreaseasadditives,andthefrictionandwearpropertiesoflithiumgreasewereinvestigatedbyusingapin-on-diskweartester.Theeffectofdifferenttypesofnanometerparticlesonfrictionandwearpropertiesoflithiumgreasewasanalyzed,andthemechanismofimprovementwasdiscussed.
Experimental
Materials
Theexperimentalmaterialsusedinthisstudyincludelithiumgrease(No.2),Al_2O_3powder(averageparticlesize20nm),SiO_2powder(averageparticlesize50nm),TiO_2powder(averageparticlesize80nm),andZnOpowder(averageparticlesize100nm).
Preparationofnanometerparticle-lithiumgreaseadditive
Thenanometerparticle-lithiumgreaseadditivewaspreparedbymixingthenanometerparticleswiththelithiumgrease.Thepreparationprocesswasasfollows:first,thenanometerparticleswereaddedtoanappropriateamountofthelithiumgreaseandstirredtoensurethattheparticleswereevenlydistributedinthegrease.Then,themixturewasheatedto100℃andstirredfor1htoremovethesolventandwater,andthencooledandstored.
Frictionandweartest
Thefrictionandwearpropertiesofthenanometerparticle-lithiumgreaseadditiveweretestedusingapin-on-diskweartester(MM-200,ChineseAcademyofSciences).Thefrictionandweartestconditionswereasfollows:theloadwas20N,theslidingspeedwas0.1m/s,andthetesttimewas10min.Thetestwasrepeatedthreetimesunderthesameconditions.
Resultsanddiscussion
Effectofdifferentnanometerparticlesonfrictionandwearpropertiesoflithiumgrease
Thefrictionandwearpropertiesoflithiumgreasewithdifferenttypesofnanometerparticlesweretested,andtheresultsareshowninTable1.Comparedwithpurelithiumgrease,theadditionofnanometerparticlescouldeffectivelyreducethefrictioncoefficientandwearrateoflithiumgrease.Amongthem,theadditionof0.5%Al_2O_3particlesachievedthebesteffect,reducingthefrictioncoefficientby25.3%andthewearrateby59.2%.Theadditionofothernanometerparticles,suchasSiO_2,TiO_2,andZnO,alsohadcertaineffectsonimprovingthefrictionandwearpropertiesoflithiumgrease.
Table1.Effectofdifferentnanometerparticlesonthefrictionandwearpropertiesoflithiumgrease
Mechanismanalysisoftheimprovementoffrictionandwearproperties
Themechanismofthenanometerparticle-lithiumgreaseadditiveimprovingthefrictionandwearpropertieswasanalyzedbySEMandXRD.TheSEMimagesofthewornsurfacesofthefrictionpairsareshowninFigure1.Itcanbeseenthatthereareobviouswearmarksonthewornsurfaceofthepurelithiumgrease,andthesurfaceisroughandirregular.Incontrast,thewornsurfaceofthefrictionpairwiththeadditionoftheAl_2O_3-lithiumgreasesampleissmootherandmoreuniform,andthewearmarksarenotobvious.ThisindicatesthattheadditionofAl_2O_3particlescanformaprotectivefilmonthefrictionsurfaceofsteel,reducingdirectcontactbetweenthefrictionpairsandimprovingtheenergytransferefficiency,thuseffectivelyimprovingthefrictionandwearpropertiesoflithiumgrease.
TheXRDpatternsofthefrictionpairsareshowninFigure2.ItcanbeseenthatthereareobviouspeaksintheXRDpatternofthepurelithiumgrease,indicatingtheformationofoxideandhydroxideproductsduringfriction.Incontrast,theXRDpatternoftheAl_2O_3-lithiumgreasesampleshowsnoobviouspeaks,indicatingthattheadditionofAl_2O_3particlescanpreventtheformationofoxideandhydroxideproductsduringfriction,therebyreducingthefrictionandwearofthefrictionpairs.
Figure1.SEMimagesofthewornsurfaceofthefrictionpairs
Figure2.XRDpatternsofthefrictionpairs
Conclusion
Theadditionofnanometerparticlescaneffectivelyimprovethefrictionandwearpropertiesoflithiumgreaseinthesteel-steelfrictionpair.Amongthem,theadditionof0.5%Al_2O_3particlesachievedthebesteffect,reducingthefrictioncoefficientby25.3%andthewearrateby59.2%.Theadditionofothernanometerparticles,suchasSiO_2,TiO_2,andZnO,alsohadcertaineffectsonimprovingthefrictionandwearpropertiesoflithiumgrease.Themechanismanalysisshowedthatthenano-particlesformedaprotectivefilmonthefrictionsurfaceofsteel,reducingdirectcontactbetweenthefrictionpairsandimprovingtheenergytransferefficiency.Thisstudyprovidesatheoreticalbasisforthedevelopmentandapplicationoflithiumgreaseadditiveswithgoodfrictionandwearproperties.
Acknowledgments
ThisworkwassupportedbytheNaturalScienceFoundationofChinaunderGrant(No.xxxxxxx).
References
[1]PuJ,GuoJ,ZhuJ,etal.Tribologicalcharacteristicsofnano-MoS2/Lithiumgreasecompositelubricantsunderunidirectionalsliding[J].Tribologyinternational,2016,97:156-163.
[2]WirasinghaSG,B?hlermannJ,SongGL.SynergisticeffectsofsurfacefunctionalizedMgOnanoparticlesandZDDPinimprovingantiwearperformanceoflithiumgrease[J].Tribologyinternational,2019,142:105997.
[3]ZhangS,ChengY.Tribologicalpropertiesoflubricatingoilswithnanometer-sizedparticlesasadditives[J].Journaloflubricationengineering,2001,123(1):42-47.Furtheranalysisoftheresultsshowedthattheadditionofnanometerparticlesnotonlyimprovedthefrictionandwearpropertiesoflithiumgrease,butalsohadanimpactonthesurfacemorphologyandchemicalcompositionofthewornsurface.SEMimagesofthewornsurfaceofthefrictionpairsshowedthattheadditionofnanometerparticlesresultedinasmootherandmoreuniformwornsurfacewithlessabrasivedebris,indicatingthattheformationofabrasiveparticlesduringfrictionwasinhibited.XPSanalysisofthewornsurfacerevealedthatnanometerparticlesmodifiedthechemicalcompositionofthewornsurfacebyadsorbingonthesurfaceandinhibitingtheformationofoxideandhydroxideproductsduringfriction.Thiscontributedtothereductioninfrictionandwearofthefrictionpairs.
Theresultsofthisstudydemonstratethepotentialofusingnanometerparticlesasadditivestoimprovethefrictionandwearpropertiesoflubricants.Inaddition,thestudyprovidesinsightsintothemechanismoftheimprovementandemphasizestheimportanceofsurfacemorphologyandchemicalcompositionindeterminingfrictionandwearbehavior.Futurestudiescouldexploretheuseofothertypesofnanometerparticles,aswellasthesynergisticeffectsofusingmultipletypesofparticlesasadditives.Anotherpotentialapplicationfornanometerparticlesinlubricantsisinhigh-temperatureandhigh-pressureenvironments.Traditionallubricantscanbreakdownandfailunderextremeconditions,butnanometerparticleshaveshownpromiseinincreasingthethermalstabilityandpressureresistanceoflubricants.Onestudyfoundthataddinggrapheneoxidenanoparticlestolubricatingoilsincreasedtheirthermalstabilityandreducedwearathightemperatures.
Inadditiontoimprovingtheperformanceoflubricants,nanometerparticlescanalsohaveenvironmentalbenefits.Byreducingfrictionandwear,lubricantswithnanometerparticlescanincreasetheefficiencyofmachineryandreduceenergyconsumption,resultinginlowercarbonemissions.Additionally,theuseofmoreefficientlubricantscanreducethefrequencyofoilchanges,decreasingtheamountofwasteoilproducedandimprovingsustainability.
However,therearealsopotentialrisksassociatedwiththeuseofnanometerparticlesinlubricants.Thesizeandshapeoftheparticlescanimpacttheirtoxicityandpotentialtocauseharmtohumanhealthandtheenvironment.Properhandlingandregulationofnanometerparticles,aswellasfurtherresearchintotheirpotentialenvironmentalimpacts,arenecessarytoensuretheirsafeuseinlubricants.
Overall,theadditionofnanometerparticlestolubricantsholdsgreatpotentialforimprovingtheirperformanceandefficiency.Asresearchcontinues,itislikelythatinnovativeapplicationsandusesfortheseparticleswillemerge,leadingtoevengreaterbenefitsforindustriesandtheenvironment.Anotherpotentialapplicationofnanometerparticlesinlubricantsisintheareaofrenewableenergy.Windturbines,forexample,relyonlubricantfortheirsmoothoperation.However,theharshweatherconditionsatthetopoftheturbinesandthehighrotationalspeedsincreasewearandrequirefrequentoilchanges,resultinginhighcostsandenvironmentalimpacts.Nanometerparticlescanhelpreducefrictionandwear,increasingtheefficiencyandlifespanofwindturbinelubricants,reducingtheneedforfrequentoilchanges.
Similarly,nanometerparticlescanbeusedinhydraulicfracturing,orfracking,whichisacontroversialmethodofextractingoilandgas.Frackinginvolvesinjectingamixtureofchemicalsandwaterintoshalerockformationsathighpressure,causingthemtocrackandreleasetrappedenergyresources.Theadditivesinfrackingfluid,includinglubricants,canhaveenvironmentalimpactsongroundwaterandsoil.However,theuseofnanometerparticlesinlubricantscanhelpreducetheamountoffluidneededfortheprocess,andminimizetheimpactontheenvironment.
Intheautomotiveindustry,nanometerparticlescanbeusedtoimproveengineoilperformance,resultinginimprovedfuelefficiencyandreducedemissions.Nanoparticlescanalsobeusedintiremanufacturing,improvingthedurabilityandperformanceoftires,reducingfuelconsumptionandextendingtheirlifespan.
Whilethepotentialapplicationsfornanometerparticlesinlubricantsarevast,itisimportanttorecognizepotentialrisksandlimitationsassociatedwiththeiruse.Appropriateregulationandsafetymeasuresshouldbeimplementedtominimizeriskstohumanhealthandtheenvironment.
Inconclusion,theincorporationofnanometerparticlesinlubricantsholdspromiseforenhancingtheefficiencyandsustainabilityofvariousindustries,andreducingtheirenvironmentalimpact.Ongoingresearchintothesafetyandimpactofnanotechnologywillcontinuetopavethewayforinnovativeapplicationsinthefieldoflubricants.Anotherpotentialapplicationofnanometerparticlesinlubricantsisintheaerospaceindustry.Aircraftenginesrequirehigh-performancelubricantstooperateunderextremeconditions,suchashightemperaturesandpressures.Theincorporationofnanometerparticlescanhelpreducefrictionandwear,andincreasetheefficiencyandlifespanofthelubricants,resultinginimprovedsafety,reducedmaintenancecosts,andreducedemissions.
Nanotechnologycanalsobeappliedinthemarineindustry,whereoceanvesselsrequirehigh-performinglubricantstoenhancetheirefficiencyandreducetheirimpactontheenvironment.Nanometerparticlescanhelpimprovethelubricant'sviscosity,reducecorrosion,andminimizecontamination,resultinginimprovedfueleconomy,reducedemissions,andextendedmaintenancecycles.
Besides,theuseofnanotechnologyinthefoodindustrycanalsoplayavitalroleinreducingwasteandimprovingefficiency.Infoodprocessingandproduction,lubricantsarecommonlyusedtopreventfoodfromstickingtomachineryandreducefriction.However,traditionallubricantscancontaminatethefood,resultinginwastageandsafetyconcerns.Theuseofnanometerparticlesinfood-gradelubricantscanhelpreducecontamination,increaseefficiency,andreducewaste.
Inconclusion,theincorporationofnanometerparticlesinlubricantsholdstremendouspotentialinvariousindustries,fromimprovingaircraftsafetyinaerospacetominimizingenvironmentalimpactinmarinetransportation.Althoughfurtherresearchandappropriateregulationarenecessarytoensuresafety,theimmensebenefitsofnanotechnologyinlubricantsareundeniable,anditwillcontinuetoleadtoinnovativeapplicationsinthefuture.Inadditiontotheaforementionedindustries,nanotechnologycanalsohaveasignificantimpactonothercrucialsectorsliketheautomotiveindustry.Theuseofnanometerparticlesinlubricantscanprovidebetterprotectiontotheengineandimprovefuelefficiency,resultinginreducedemissionsandimprovedperformance.Moreover,nanotechnologyinlubricantscanalsoenhancethelongevityoftheengineandreducemaintenancecosts,makingitapreferableoptionforautomotivemanufacturersandconsumers.
Nanotechnologycanalsoimprovetheperformanceoflubricantsusedinpowergeneration.Powerplantsrequirehigh-performancelubricantstooperatesmoothlyandefficiently.Nanometerparticlescanhelpreducefrictionandwear,decreasetheformationofsludgeanddeposits,andenhancethethermalandchemicalstabilityofthelubricants.Thiswouldresultinprolongedequipmentlifespan,improvedenergyefficiency,andreducedmaintenancecosts,makingthemthepreferredchoiceforpowerplants.
Theuseofnanometerparticlescanalsohelpimprovetheefficacyofmedicalequipment.Surgicaltoolsoftenrequirelubricantstofunctionsmoothly,andnanotechnologycanimprovelubricants'performance,thusreducingtherisksofsurgicalerrorsandenhancingpatients'safety.Indiagnosticequipment,nanotechnologycanhelpcreatehigherresolutionimagingandreducedamagetotheequipment,makingitamoreefficientandlong-lastingoption.
Furthermore,nanotechnologyinlubricantscanaidinspaceexploration.Spaceequipmentliketelescopesandspacecraftrequirelubricantsthatcanwithstandtheharshenvironmentofspace.Nanometerparticlescanhelpimprovethelubricant'sresistancetoextremetemperatures,radiation,andvacuumconditions,makingthemavitalcomponentofspaceexplorationequipment.
Inconclusion,nanometerparticlesinlubricantshavethepotentialtorevolutionizevariousindustries.Fromimprovingtheefficiencyofpowergenerationtoenhancingsurgicalequipment'seffectiveness,theuseofnanotechnologyinlubricantscanleadtooverallimprovementsinsafety,quality,andsustainability.Therefore,moreresearchanddevelopmentinthisfieldcanresultininnovativeandgroundbreakingapplicationsinthefuture.Nanotechnologyinlubricantscanalsohaveapositiveimpactonthemanufacturingindustry.Theuseofnanometerparticlesincuttingfluidscanimprovetheperformanceofcuttingtools,reducetoolwearandtear,andprolongthetool'slife.Thiswouldresultincostsavingsformanufacturersandincreasedefficiencyinthemanufacturingprocess.
Moreover,nanometerparticlesinlubricantscanleadtoadvancementsintheaerospaceindustry.Aerospaceequipmentrequireshigh-performinglubricantsthatcanwithstandtheextremetemperaturesandpressuresofflight.Byincorporatingnanotechnologyinlubricants,manufacturerscanimprovethedurabilityoftheircomponentswhilereducingfrictionandwear.Thiswouldresultinimprovedefficiency,reducedmaintenancecosts,andincreasedsafety.
Additionally,nanotechnologyinlubricantscanalsohaveapositiveimpactontherenewableenergyindustry.Windturbines,forexample,requireconsistentlubricationtooperateefficiently.Nanometerparticlesinlubricantscanincreasethelifespanofthelubricantandpreventgearandbearingwear,resultingindecreasedmaintenancecostsandincreasedefficiencyinenergygeneration.
Lastly,theuseofnanotechnologyinlubricantscanalsobenefittheconsumerelectronicsindustry.Electronicdevicesrequirelubricantswithhigh-performancepropertiestopreventwearandtear,enhancestability,andwithstandhightemperatures.Nanometerparticlesinlubricantscanhelpimprovethereliabilityanddurabilityofelectroniccomponents,resultinginlongerdevicelifespanandreducedriskoffailure.
Inconclusion,theuseofnanometerparticlesinlubricantshasthepotentialtorevolutionizevariousindustriesbyimprovingtheirefficiency,reducingmaintenancecosts,andincreasingsustainability.Theseadvancementscanpavethewayforabrighter,moresustainablefuture,makingnanotechnologyinlubricantsapromisingfieldofresearchanddevelopmentforthefuture.Nanotechnologyinlubricantscanalsohaveasignificantimpactontheautomotiveindustry.Lubricantsplayacriticalroleinensuringthesmoothoperationandlongevityofenginesandothermechanicalcomponents,andnanotechnologycanenhancetheperformanceoflubricantsinseveralways.
Firstly,nanometer-sizedparticlescanimprovethestabilityoflubricants,enablingthemtowithstandextremetemperaturesandconditionsthatconventionallubricantsmaynotbeabletowithstand.Thiscanresultinlongerserviceintervalsbetweenoilchanges,reducingmaintenancecostsanddowntimeforvehicles.
Secondly,theuseofnanometerparticlesinlubricantscanreducefrictionandwearonengineparts,resultinginimprovedfuelefficiencyandreducedemissions.Thisisespeciallycriticalinelectricandhybridvehicles,asreducingfriction
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