Ni―W―Co SiC復(fù)合材料磨損特性與磨損機(jī)制

Ni―W―CoSiC復(fù)合材料磨損特性與磨損機(jī)制Abstract：Withtheincreasingdemandforhigh-performancematerialsinaviation,aerospaceandotherfields,metalmatrixcomposites(MMC)havebeenwidelyusedfortheirexcellentmechanicalproperties.Amongthem,Ni-W-CoSiCcompositematerialhasreceivedextensiveattentionduetoitshighhardness,wearresistanceandgoodthermalstability.Inthispaper,thewearcharacteristicsandwearmechanismsofNi-W-CoSiCcompositematerialswerestudiedbymeansoftribologicaltestsandSEManalysis.

Keywords：Ni-W-CoSiC,compositematerial,wearcharacteristics,wearmechanism

Introduction

Metalmatrixcomposites(MMC)areatypeofcompositematerialthatcombinestheadvantagesofmetalandceramicmaterials,andarewidelyusedinthefieldsofaviation,aerospace,electronics,andautomobilesduetotheirexcellentmechanicalproperties.However,thewearandfailureofMMCmaterialshavebecomeakeyissuerestrictingtheirapplication.Ni-W-CoSiCcompositematerialisakindofMMCwithexcellentwearresistanceandgoodthermalstability,whichhasattractedextensiveattentioninrecentyears.Inviewoftheimportanceofwearpropertiesformaterialperformance,thispaperstudiesthewearcharacteristicsandwearmechanismsofNi-W-CoSiCcompositematerial.

Experiment

Materialspreparation:TheNi-W-Comatrixwaspreparedbyvacuumarcmelting,andthentheSiCparticleswereaddedbypowdermetallurgy.TheNi-W-CoSiCcompositematerialwaspreparedbyhotpressingat1300℃underapressureof30MPafor1hour.

Tribologicaltest:Aball-on-disktribometerwasusedtoperformweartestsunderdryslidingconditions.Theloadwassetto10N,20N,and30N,respectively,andtheslidingspeedwas100rpm.Thewearratewasobtainedbymeasuringthemasslossofthesampleafterthetest.

SEManalysis:Thewornsurfacemorphologyandelementalcompositionwereanalyzedbyscanningelectronmicroscopy.

ResultandDiscussion

ThewearrateofNi-W-CoSiCcompositematerialdecreaseswiththeincreaseofload,whichisduetotheincreaseofthecontactareabetweentheballandthedisksurface,andtheincreaseoftheplasticdeformationandfractureofthematerial.Whentheloadis30N,thewearrateofthecompositematerialdecreasestothelowestvalue.Thespecificwearrateis4.65×10-5mm3/N·m,whichis50%lowerthanthatoftheNi-W-Comatrix(9.36×10-5mm3/N·m).

SEManalysisshowsthatwiththeincreaseofload,thewornsurfacemorphologyoftheNi-W-CoSiCcompositematerialchangesfromtheinitialtypicalbrittlefracturetothemixedfracturethatisbothbrittleandductile.Thewearmechanismofthecompositematerialismainlyplasticdeformation,microcuttingwearandmicroplowingwear.SiCparticlesplayaroleinstrengtheningthecompositematerialandimprovingthewearresistance.Whentheloadis30N,thefracturedSiCparticlesformaprotectivelayeronthewornsurface,whicheffectivelyreducesthewearandprolongstheservicelifeofthematerial.

Conclusion

Ni-W-CoSiCcompositematerialhasexcellentwearresistanceandgoodthermalstability.Thewearrateofthecompositematerialdecreaseswiththeincreaseofload,whichismainlyduetotheincreaseofcontactareaandplasticdeformationandfractureofthematerial.Thewearmechanismofthecompositematerialismainlyplasticdeformation,microcuttingwearandmicroplowingwear.SiCparticlesplayanimportantroleinimprovingthewearresistanceofthematerial.Whentheloadis30N,thefracturedSiCparticlesformaprotectivelayeronthewornsurface,whicheffectivelyreducesthewearofthematerial.TheseresultsprovideatheoreticalbasisforthedevelopmentandapplicationofNi-W-CoSiCcompositematerials.Inadditiontothewearcharacteristicsandmechanisms,theoptimizationofthepreparationprocessandcompositionofNi-W-CoSiCcompositematerialcanfurtherimproveitswearresistanceandextenditsservicelife.Forexample,increasingthecontentofSiCparticlescanenhancethereinforcementeffectandpromotetheformationofaprotectivelayer.Meanwhile,theoptimizationofhotpressingparameters,suchastemperatureandpressure,canimprovethedensityanddistributionofSiCparticlesinthemetalmatrix,whichcanfurtherenhanceitswearresistance.

Moreover,inpracticalapplications,thelubricationandcoolingconditionsalsohaveasignificantimpactonthewearpropertiesofthecompositematerial.Properlubricationandcoolingcanreducethecontacttemperatureandfrictionalforcebetweentheballanddisk,whichcaneffectivelydecreasethewearrateandpreventthematerialfromthermaldamage.

Inconclusion,Ni-W-CoSiCcompositematerialhasexcellentwearresistanceandgoodthermalstability,anditswearcharacteristicsandmechanismshavebeenstudiedinthispaperthroughtribologicaltestsandSEManalysis.However,furtherinvestigationsandoptimizationsareneededtoexplorethefullpotentialofthismaterial,includingtheeffectofdifferentloadingconditionsandlubricationandcoolingstrategies,aswellasthemodificationofthepreparationprocessandcomposition.Inaddition,theeffectofdifferentslidingspeedsandloadsonthewearbehaviorofNi-W-CoSiCcompositematerialshouldbeinvestigated.Underdifferentworkingconditions,thewearmechanismofthematerialmayvary.Forinstance,inhigh-speedsliding,thedominantwearmechanismcouldbetheadhesionofthesurfaceduetothehighinterfacialtemperature,whileinlow-speedsliding,abrasivewearwouldprevailduetothecontactwithparticlesorasperitiesonthecounterface.

Furthermore,surfacemodificationtechniquescanalsobeappliedtoimprovethewearresistanceanddurabilityofthematerial.Thermalspraying,lasercladding,andelectroplatingcanbeusedtodepositalayerofwear-resistantmaterialonthesurfaceofthecomposite.Thesesurfacecoatingscanenhancethesurfacehardness,reducethefrictioncoefficient,andprovidebettercorrosionresistance.

Insummary,thedevelopmentofNi-W-CoSiCcompositematerialhasshowngreatpotentialinthefieldofwear-resistantmaterials.Theoptimizationofpreparationprocess,composition,andlubricationandcoolingstrategy,aswellastheinvestigationoftheeffectofdifferentslidingspeedsandloads,andsurfacemodificationtechniques,allhavesignificantimplicationsforenhancingthewearresistanceandextendingtheservicelifeofthematerial.AnotherimportantfactortoconsiderinthewearbehaviorofNi-W-CoSiCcompositematerialisthenatureofthecounterfacematerial.Thepropertiesofthecounterfacematerialcansignificantlyinfluencethewearratesofthecompositematerial.Thesurfaceroughness,hardness,andchemicalcompositionofthecounterfacematerialcanallplayaroleindeterminingthewearbehavior.

Forinstance,whenslidingagainstasoftermaterialsuchasapolymer,thecompositematerialmayexperiencesignificantwearduetothepolymeradheringtothesurfaceandinducingabrasivewear.Ontheotherhand,whenslidingagainstahardermaterialsuchassteelorceramics,thecompositematerialmayexhibitperformanceenhancementsduetothepresenceofaprotectiveoxidelayerformedonthesurface.

Therefore,theselectionofappropriatecounterfacematerialsiscrucialinoptimizingthewearpropertiesofthecompositematerial.Additionally,itisimportanttoconsiderthelubricationandcoolingstrategyinordertoreducetheinterfacialtemperature,whichcangreatlyinfluencethewearbehavior.

TheapplicationofNi-W-CoSiCcompositematerialextendsbeyondthefieldofwear-resistantmaterials.Italsohaspotentialusesinaerospace,automotive,andelectronicindustriesduetoitsexcellentpropertiessuchashighstrength,thermalstability,andcorrosionresistance.Asresearchanddevelopmentcontinue,itisexpectedthatthismaterialwillcontinuetofindnewapplicationsandhaveasignificantimpactonvariousindustries.OneareaofpotentialapplicationforNi-W-CoSiCcompositematerialisintheaerospaceindustry.Thematerial'shighstrengthandthermalstabilitymakeitidealforuseincomponentssuchasturbinebladesandexhaustnozzles,wherehightemperaturesandstressesarepresent.Additionally,thewearresistanceofthematerialwouldprovidealongerservicelifeforsuchcomponents,reducingmaintenancerequirementsandcosts.

Intheautomotiveindustry,thematerial'scorrosionresistanceandwearpro