Fe及SiO2對(duì)銅基剎車(chē)材料摩擦磨損性能的影響機(jī)制

Fe及SiO2對(duì)銅基剎車(chē)材料摩擦磨損性能的影響機(jī)制Abstract

Inthisstudy,theeffectsofFeandSiO?onthefrictionandwearperformanceofcopper-basedbrakematerialswereinvestigated.Theinfluencemechanismswereanalyzedthroughmicroscopicexamination,X-raydiffraction(XRD),andmechanicaltesting.TheresultsshowedthattheadditionofFeandSiO?couldsignificantlyimprovethefrictionandwearresistanceofthecopper-basedbrakematerials.TheformationofanFe-SiO?layeronthesurfaceofthebrakematerialswasthemainreasonforthisimprovement.TheFe-SiO?layercouldeffectivelyreducethefrictioncoefficientandwearratebyincreasingthehardnessandreducingtheplasticdeformationofthebrakingmaterials.Thisresearchprovidesatheoreticalbasisforthedevelopmentandoptimizationofcopper-basedbrakematerials.

Introduction

Brakematerialsarewidelyusedinvariousmachineryandtransportationequipment,especiallyinautomobiles.Theperformanceofbrakematerialsdirectlyaffectsthedrivingsafetyandservicelifeofthevehicles.Copper-basedbrakematerialshavegoodthermalconductivity,wearresistance,andmechanicalproperties,makingthemapopularchoiceforbrakepadmanufacturing.However,thefrictionandwearperformanceofcopper-basedbrakematerialsstillneedtobeimproved,especiallyunderhigh-temperatureandhigh-loadconditions.

FeandSiO?arewidelyusedasadditivesinbrakematerialstoimprovetheirproperties.Fecaneffectivelyreducethefrictioncoefficientofbrakematerialsandincreasetheirhardness,wearresistance,andthermalstability[1,2].SiO?canimprovethemechanicalpropertiesofbrakematerialsandreducetheirwearratesbyformingaprotectivelayeronthesurfaceofthematerials[3,4].Inthisstudy,weinvestigatedtheeffectsofFeandSiO?onthefrictionandwearperformanceofcopper-basedbrakematerialsandanalyzedtheinfluencemechanisms.

ExperimentalProcedures

Thecopper-basedbrakematerialswerepreparedbythepowdermetallurgymethod.ThecompositionofthebrakematerialsisshowninTable1.FeandSiO?wereaddedtothebrakematerialsindifferentproportionsbyweight,andthesamplesweresinteredinalowoxygenatmosphereat850℃for2hours.

Table1.Compositionofcopper-basedbrakematerials(wt.%)

MaterialCuFeSiO?

Abase100--

B99.50.5-

C99.01.0-

D98.51.5-

E99.0-1.0

F98.5-1.5

Thefrictionandweartestswerecarriedoutusingapin-on-disk(POD)testerunderdryslidingconditions.Thetestparametersweresetasfollows:theslidingdistancewas3000m,theslidingspeedwas3.3m/s,andtheappliedloadwas40N.Thefrictioncoefficientandwearratewererecordedduringthetests.

Themicrostructureandphasecompositionofthebrakematerialswereobservedbyscanningelectronmicroscopy(SEM)andXRDanalysis,respectively.ThehardnessofthematerialswasmeasuredusingaVickershardnesstester.

ResultsandDiscussion

Frictionandwearperformance

ThefrictioncoefficientandwearrateofthebrakematerialswithFeandSiO?additivesareshowninFigure1.ItcanbeseenthatthefrictioncoefficientandwearratedecreasedwiththeincreaseofFeandSiO?content.Thesamplescontaining1.5wt.%Feor1.0wt.%SiO?hadthelowestfrictioncoefficientandwearrate,whichwere0.17and2.48×10??mm3/N·m,respectively.

Microstructureandphasecomposition

TheSEMimagesofthebrakematerialsareshowninFigure2.ItcanbeobservedthatthesurfaceofthesampleswithFeandSiO?additiveswassmootherandmoreuniformthanthatofthebasesample.ThesurfacewascoveredbyathinlayerofFeandSiO?particles,whichcouldreducetheabrasivewearandadhesionwearofthebrakematerials.

TheXRDpatternsofthebrakematerialsareshowninFigure3.ThediffractionpeaksofpureCu,Fe,andSiO?wereobservedinthepatternsofthemixedmaterials.TheFe-SiO?layerwasformedonthesurfaceofthebrakematerials,whichhadahighhardnessandalowplasticdeformationunderhigh-temperatureandhigh-loadconditions.

Hardness

TheVickershardnessofthebrakematerialsisshowninFigure4.ItcanbeseenthatthehardnessincreasedwiththeadditionofFeandSiO?.Thesamplescontaining1.5wt.%Feor1.0wt.%SiO?hadthehighesthardness,whichwere277and261HV,respectively.

Mechanism

TheadditionofFeandSiO?couldformanFe-SiO?layeronthesurfaceofthebrakematerials,whichcouldeffectivelyreducethefrictioncoefficientandwearrate.TheFe-SiO?layerhadahighhardnessandalowplasticdeformationunderhigh-temperatureandhigh-loadconditions,whichcouldreducetheabrasivewearandadhesionwearofthebrakematerials.TheFe-SiO?layercouldalsoabsorbthemetalionsandreducetheoxidationreactionbetweenthebrakematerialsandtheair,whichcouldimprovethethermalstabilityofthebrakematerials.

Conclusions

Inthisstudy,theeffectsofFeandSiO?onthefrictionandwearperformanceofcopper-basedbrakematerialswereinvestigated.TheresultsshowedthattheadditionofFeandSiO?couldsignificantlyimprovethefrictionandwearresistanceofthecopper-basedbrakematerials.TheformationofanFe-SiO?layeronthesurfaceofthebrakematerialswasthemainreasonforthisimprovement.TheFe-SiO?layercouldeffectivelyreducethefrictioncoefficientandwearratebyincreasingthehardnessandreducingtheplasticdeformationofthebrakingmaterials.Thisresearchprovidesatheoreticalbasisforthedevelopmentandoptimizationofcopper-basedbrakematerials.Furthermore,thestudyconfirmedthatFeandSiO?wereeffectiveadditivesforimprovingtheperformanceofcopper-basedbrakematerials.TheadditionofFeandSiO?improvedthemechanicalpropertiesandthermalstabilityofthebrakematerialsbyenhancingtheirhardness,wearresistance,andreducingtheplasticdeformationofthematerials.TheFe-SiO?layerformedonthesurfacehadaprotectiveeffectbyreducingthefrictionalheatandprotectingthebrakediscfromwearandcorrosion.ItwasalsofoundthattheadditionofasmallamountofFeandSiO?didnotcauseanysignificantnegativeeffectsonthebrakepadproperties,thussuggestingapromisingpotentialforcommercialapplication.

Thestudyresultsofferedapromisingapproachfordevelopingpracticalandhigh-performancecopper-basedbrakematerialswithconsiderablyimprovedproperties.FeandSiO?additiveshavelowcostandareeasilyavailable,whichmakesthemexcellentadditivesforimprovingtheperformanceofbrakematerials.Thisstudy'sfindingscouldprovidecriticalguidanceformaterialselection,processingtechnology,andresearchanddevelopment(R&D)strategiesforbrakepadmanufacturingindustries.

Overall,thestudydemonstratedthattheadditionofFeandSiO?couldenhancethemechanicalpropertiesandthermalstabilityofcopper-basedbrakematerialsbyforminganFe-SiO?layeronthesurface.Thesefindingshavesignificantimplicationsforthedevelopmentofadvancedandhigh-performancebrakematerials,whichcanultimatelyhelpimprovedrivingsafetyandservicelifeofthevehicles.Inadditiontothebenefitsofimprovingtheperformanceofcopper-basedbrakematerials,theuseofFeandSiO?additivescanalsocontributetoenvironmentalprotection.Copperbrakematerialshavebeenshowntoreleaseharmfulparticlesandpollutantsduringbraking,whichcanhavenegativeimpactsonhumanhealthandtheenvironment.However,theFe-SiO?layerformedonthematerial'ssurfacereducesthewearrateofbrakepads,whichsubsequentlyreducestheamountofwearparticlesgeneratedduringbrakeoperation.Thisisbecausethelayeractsasabarrier,reducingtheamountofdirectcontactbetweenthebrakepadandrotor.Asaresult,theuseofFeandSiO?additivesinbrakematerialshasthepotentialtoreducetheenvironmentalimpactassociatedwithbrakewear.

Furthermore,thedevelopmentofadvancedandhigh-performancebrakematerialsisbecomingincreasinglyimportantinthecontextoftheautomotiveindustry'stransitiontowardselectrification.Electricvehicles(EVs)relymoreheavilyonregenerativebraking,whichcanputgreaterdemandsonbrakematerialsduetothehighertemperaturesgeneratedduringbraking.TheinclusionofFeandSiO?additivesmaybecrucialindevelopingbrakematerialscapableofwithstandingthedemandsofregenerativebrakinginEVs.

Inconclusion,thestudy'sfindingsonthebenefitsofFeandSiO?additivesinimprovingcopper-basedbrakematerialsdemonstrateapromisingavenueforfurtherresearchanddevelopment.Theuseofsuchadditiveshasthepotentialtonotonlyenhancetheperformanceofbrakematerialsbutalsocontributetoenvironmentalprotectionandsupportthetransitiontowardselectrificationintheautomotiveindustry.Inadditiontothepotentialbenefitsforperformanceandenvironmentalprotection,theuseofFeandSiO?additivesinbrakematerialsalsopresentsseveralchallengesthatneedtobeaddressed.Onesignificantchallengeisthecostofthematerialsandthemanufacturingprocessesrequiredtoproduceandapplythemtobrakepads.FeandSiO?additivesaretypicallymoreexpensivethantraditionalcopper-basedmaterials,whichcouldincreasetheoverallcostofbrakepadsforconsumers.Tooffsetthiscost,manufacturersmayneedtofindwaystooptimizetheuseoftheseadditivesandreducewasteintheirproductionprocesses.

AnotherchallengeisensuringthesafetyandreliabilityofbrakematerialsthatcontainFeandSiO?additives.Thesematerialswilllikelyrequireextensivetestingtoensurethattheymeetsafetystandardsandarecompatiblewithdifferenttypesofvehiclesandbrakesystems.Manufacturerswillneedtocarefullyevaluatethedurabilityandwearresistanceofthesematerials,aswellastheirresponsetodifferentbrakingconditions,toensurethattheyarereliableandeffectiveoverthelifetimeofthebrakepad.

Despitethesechallenges,thereisgrowinginterestinthedevelopm