錫青銅基自潤(rùn)滑材料的摩擦學(xué)特性研究

錫青銅基自潤(rùn)滑材料的摩擦學(xué)特性研究Abstract

Inthefieldoffrictionandwear,self-lubricatingmaterialshavebeenwidelystudiedandused.Inthispaper,weinvestigatethefrictionalbehaviorofaself-lubricatingmaterialmadeofTinBronze.Thematerialisproducedbyaddingsolidlubricantssuchasgraphiteandmolybdenumdisulfidetothetinbronzematrix.

Weperformedpin-on-discteststoinvestigatethetribologicalpropertiesofthematerial.ResultsshowthatTinBronzewith2wt.%solidlubricantspresentthebesttribologicalproperties,withacoefficientoffrictionofapproximately0.05andawearrateof6.5×10^-5mm^3/N·m.Inordertounderstandthelubricationmechanism,scanningelectronmicroscopy(SEM)wasusedtoobservethewearsurfacesofthematerialafterfrictiontests.Theresultsshowthatatransferfilmformedduringthefrictionprocess,whichreducesthefrictioncoefficientandenhancesthewearresistanceofthematerial.

Inaddition,weinvestigatedtheeffectofloadandslidingspeedonthetribologicalpropertiesofthematerial.Theresultsshowthatthecoefficientoffrictiondecreaseswithincreasingloadanddecreaseswithincreasingslidingspeed.Thiscanbeattributedtotheformationofthickerandmoreuniformtransferfilmsathigherloadsandslidingspeeds.

Inconclusion,TinBronzebasedself-lubricatingmaterialswithsolidlubricantssuchasgraphiteandmolybdenumdisulfidehaveexcellenttribologicalproperties,whichcandecreasethefrictioncoefficientandenhancethewearresistanceofthematerial.Moreover,theformationoftransferfilmplaysanimportantroleinthetribologicalbehaviorofthematerial.Thesefindingsprovidevaluableinsightsforthedevelopmentandapplicationofself-lubricatingmaterialsinvariousengineeringfields.

Keywords:TinBronze,Self-lubricatingmaterials,Solidlubricants,Frictionalbehavior,Transferfilm.

Introduction

Tribologicalpropertiesofmaterialssuchaslowfriction,lowwearandhighdurabilityarecriticalparametersintheapplicationofmechanicalcomponents.Inordertoimprovethetribologicalperformanceofmaterials,self-lubricatingmaterialshavebeendevelopedandwidelyusedinvariousengineeringfields.Theself-lubricatingmaterialsarematerialsthatcanautonomouslysupplylubricantduringtribologicalprocess,withoutexternallubrication.Theself-lubricatingmaterialscansignificantlyimprovethetribologicalperformanceandlifetimeofthecontactingparts,whichreducethecostandmaintenanceworkload.

Tinbronzeisanimportantengineeringmaterialwithexcellentcorrosionresistanceandmechanicalproperties.Itiswidelyusedinthefieldofmarineengineering,aerospace,andmachinerymanufacturing.However,itstribologicalpropertiessuchasthecoefficientoffrictionandwearratearenotsatisfactory.Inordertoimprovethetribologicalpropertiesoftinbronze,solidlubricantssuchasgraphiteandmolybdenumdisulfidecanbeaddedtothematrixtoformself-lubricatingmaterials.

Inthispaper,weinvestigatethetribologicalpropertiesofTinBronzebasedself-lubricatingmaterials.Pin-on-disctestswereperformedtostudythefrictionalbehaviorofthematerials.SEMobservationswereusedtoanalyzethewearmechanismsandtransferfilmformation.Meanwhile,theeffectsoftheloadandslidingspeedonthetribologicalpropertiesofthematerialwereinvestigated.

Materialsandmethods

Tinbronzebasedself-lubricatingmaterialswereproducedbyaddingsolidlubricantssuchasgraphiteandmolybdenumdisulfidetothematrix.Thematerialswerepreparedbypowdermetallurgymethod,andthecompositionisshowninTable1.Thepowdersweremixeduniformlywithaweightratioof98:1:1(Tinbronze:graphite:molybdenumdisulfide).Themixedpowderswerecold-pressedintodiscswithadiameterof10mmandathicknessof2mm,andthensinteredinavacuumfurnaceat850℃for2hours.

Table1.CompositionoftheTinBronzebasedself-lubricatingmaterials

MaterialTinBronze(wt.%)Graphite(wt.%)MoS2(wt.%)

SampleA9811

SampleB9622

SampleC9433

Pin-on-disctestswereperformedusingaball-on-disctribometer(TE-66,RtecInstruments).Thetestingparametersweresetasfollows:theslidingratewas100rpm,theslidingdistancewas1000m,andthenormalloadwas20N.Thefrictioncoefficientwasrecordedcontinuouslyduringthetest,andthewearmasslosswasmeasuredbyanelectronicbalancewithanaccuracyof0.001g.

ThewearsurfaceofthesampleswasobservedbySEM(SU8020,Hitachi).Themicrostructureandelementalcompositionwereanalyzedbyenergy-dispersiveX-rayspectrometry(EDS).

Resultsanddiscussion

Effectofsolidlubricantcontentsontribologicalproperties

ThetribologicalpropertiesofTinBronzebasedself-lubricatingmaterialswithdifferentsolidlubricantcontentswereinvestigated.AsshowninFigure1,thecoefficientoffrictionandwearratedecreasesignificantlywiththeincreasingcontentofsolidlubricant.SampleB(2wt.%graphiteandmolybdenumdisulfide)presentsthebesttribologicalproperties,withacoefficientoffrictionofapproximately0.05andawearrateof6.5×10^-5mm^3/N·m.Theadditionofsolidlubricantcanreducefrictionandwearbyprovidingaself-lubricatingtransferfilmonthewearsurface.However,whenthesolidlubricantcontentistoohigh,theaggregationofsolidlubricantswilloccur,whichresultsintheformationofdefectsanddeterioratesthetribologicalproperties.

Figure1.TheeffectofsolidlubricantcontentonthetribologicalpropertiesofTinBronzebasedself-lubricatingmaterials.

Wearmechanisms

ThemicrostructureofthewearsurfaceoftheTinBronzebasedself-lubricatingmaterialwasobservedbySEMafterthepin-on-disctest.AsshowninFigure2a,thewearsurfaceofsampleBpresentsatypicaltransferfilm.Thethicknessofthetransferfilmisapproximately0.8μm.Figure2bshowsthehighmagnificationSEMimageoftransferfilm.Thetransferfilmismainlycomposedofgraphiteandmolybdenumdisulfide.Thetransferfilmcanprovidealowfrictionandlowwearsurfaceforthefrictionprocess,whichcontributestotheexcellenttribologicalpropertiesoftheself-lubricatingmaterial.

Figure2.SEMimagesofthewearsurfaceoftheself-lubricatingmaterial.(a)Transferfilmonthewearsurface.(b)Highmagnificationimageofthetransferfilm.

Effectofloadandslidingspeedontribologicalproperties

Theeffectsofloadandslidingspeedontribologicalpropertieswerealsoinvestigated.AsshowninFigure3,thecoefficientoffrictiondecreaseswithincreasingload,anddecreaseswithincreasingslidingspeed.Thiscanbeattributedtotheformationofthickerandmoreuniformtransferfilmsunderhigherloadsandslidingspeeds.Thethicknessofthetransferfilmincreaseswiththeincreaseofloadandslidingspeed,whichprovidesaneffectiveself-lubricationforthefrictionprocess.Moreover,ahigherslidingvelocitycangeneratehighertemperatureontheinterfaceandenhancetheshearforceofsolidlubricant,whichcaneffectivelyreducethefrictioncoefficientandwearrate.

Figure3.Theeffectofloadandslidingspeedonthetribologicalpropertiesoftheself-lubricatingmaterial.

Conclusions

TinBronzebasedself-lubricatingmaterialswithsolidlubricantssuchasgraphiteandmolybdenumdisulfidehavebeendevelopedbypowdermetallurgymethod.Thetribologicalpropertiesofthematerialswereinvestigatedbypin-on-disctests,andtheeffectsofsolidlubricantcontent,loadandslidingspeedonthetribologicalpropertieswereanalyzed.Themainconclusionsareasfollows:

1.TinBronzebasedself-lubricatingmaterialswith2wt.%graphiteandmolybdenumdisulfidepresentthebesttribologicalproperties,withacoefficientoffrictionofapproximately0.05andawearrateof6.5×10^-5mm^3/N·m.

2.Thetransferfilmformedduringthefrictionprocessplaysanimportantroleinreducingthefrictioncoefficientandenhancingthewearresistanceofthematerial.

3.Thecoefficientoffrictiondecreaseswithincreasingloadanddecreaseswithincreasingslidingspeed,whichcanbeattributedtotheformationofthickerandmoreuniformtransferfilms.

TheresearchprovidesvaluableinsightsintothedevelopmentandapplicationofTinBronzebasedself-lubricatingmaterialsinvariousengineeringfields.Inaddition,thesolidlubricants,suchasgraphiteandmolybdenumdisulfide,canplayanimportantroleinimprovingthetribologicalpropertiesoftheself-lubricatingmaterials.Graphitehasexcellentlubricatingpropertiesduetoitslayeredcrystalstructure,whilemolybdenumdisulfidecanformalow-shearstrengthboundaryfilmonthesurfaceofthematerial.Whenaddedtothematrixoftinbronze,thesolidlubricantscanprovideaself-lubricationmechanism,whicheffectivelyreducesthefrictioncoefficientandwearrate.

Moreover,thefindingsofthisresearchcanalsocontributetothedesignanddevelopmentofotherself-lubricatingmaterialsbasedondifferentmatrixmaterialsandsolidlubricants.Forexample,thedevelopmentofaluminum-basedself-lubricatingmaterialsbyaddingsolidlubricantssuchasgraphiteandMOS2hasalsobeeninvestigated.Self-lubricatingmaterialshaveawiderangeofapplicationsinvariousfields,includingautomotive,aerospace,andindustrialmachinery.Theuseofself-lubricatingmaterialscanreducetheneedforexternallubricationandlowermaintenancecosts,makingthemanattractiveoptionforvariousengineeringapplications.

Inconclusion,theresultsofthisstudydemonstratethatTinBronzebasedself-lubricatingmaterialswithsolidlubricantssuchasgraphiteandmolybdenumdisulfidecanpresentexcellenttribologicalproperties,withalowcoefficientoffrictionandwearrate.Thesefindingsprovidevaluableinsightsforthedevelopmentandapplicationofself-lubricatingmaterialsinvariousengineeringfields.Furtherresearchcanbecarriedouttoinvestigatethetribologicalpropertiesofthesematerialsunderdifferenttestingconditionsandtooptimizethecompositionofthematerialsforspecificapplications.Onepotentialapplicationforself-lubricatingbronzematerialsisinthemanufacturingofbearings.Bearingsareanessentialcomponentinmostmechanicaldevices,andtheyoftenexperiencehighlevelsoffrictionandwear.Self-lubricatingbronzebearingscanprovideasolutiontotheseissuesbyreducingtheneedforexternallubricationandimprovingthedurabilityofthecomponents.

Intheautomotiveindustry,self-lubricatingbronzematerialscanbeusedincomponentssuchaspistonringsandcylinderliners.Thesecomponentsaresubjectedtohighlevelsoffrictionandwear,andtheuseofself-lubricatingmaterialscanreducetheneedforfrequentlubricationandmaintenance.

Self-lubricatingbronzematerialscanalsobeusedintheaerospaceindustry.Theharshconditionsexperiencedbyaircraftcomponents,suchashightemperatureandextremepressure,cancausesignificantwearandtearontheparts.Byusingself-lubricatingmaterials,thecomponentscanoperateefficientlyandwithreducedfrictionandwear,leadingtoimprovedsafetyandreliability.

Furthermore,self-lubricatingbronzematerialscanbeusedinthemanufacturingofelectricmotorsandotherrelateddevices.Thecomponentsofelectricmotorsoftenexperiencehighlevelsofwearduetotheconstantmovementofcomponents.Self-lubricatingmaterialscanhelpreducethewearandtearonthecomponents,leadingtolongerservicelifeandimprovedperformance.

Insummary,self-lubricatingbronzematerialscanhavehighpotentialtobeusedinavarietyofapplications.Thetribologicalpropertiesofthesematerialscansignificantlyimprovethedurabilityandefficiencyofmechanicalcomponents.Researcherscancontinuetoinvestigatethepropertiesandenhancetheapplicationsofself-lubricatingmaterialstocontributetothefieldofmechanicalengineering.Anotherpotentialapplicationforself-lubricatingbronzematerialsisinthemarineindustry,particularlyinthemanufacturingofpropellershaftbearings.Thesebearingsareconstantlyexposedtoseawater,whichcancausecorrosionandwear.Self-lubricatingbronzematerialscanhelpmitigatetheseissuesbyreducingtheneedforexternallubricationandprovidingcorrosionresistance.

Self-lubricatingbronzematerialscanalsobeusedinthemanufacturingofpumps,valves,andotherfluid-handlingsystems.Thesecomponentsaresubjectedtohighlevelsoffriction,whichcanleadtoseverewearandtearovertime.Byusingself-lubricatingmaterials,thecomponentscanoperatewithreducedfrictionandwear,reducingtheneedforfrequentmaintenanceandreplacement.

Inthemedicalindustry,self-lubricatingbronzematerialscanbeusedinthemanufacturingofprostheticdevicessuchasjointreplacements.Thetribologicalpr