La-2O-3和WSi-2增强MoSi-2基复合材料的摩擦磨损性能研究

La_2O_3和WSi_2增强MoSi_2基复合材料的摩擦磨损性能研究摘要：

本文研究了La2O3和WSi2对MoSi2基复合材料摩擦磨损性能的影响。利用真空感应熔炼、热等静压和热处理工艺制备了不同添加量La2O3和WSi2的MoSi2基复合材料，并进行了摩擦磨损实验。结果表明，适量添加La2O3和WSi2可以显著提高MoSi2基复合材料摩擦磨损性能。当La2O3添加量为4％，WSi2添加量为10％时，MoSi2基复合材料的耐磨性能最佳，摩擦系数最小。

关键词：La2O3；WSi2；MoSi2；复合材料；摩擦磨损性能

Introduction:

MoSi2hasgoodhightemperaturemechanicalproperties,oxidationandcorrosionresistance,andiswidelyusedinaerospace,nuclearenergyandotherfields.However,itspoorwearresistancelimitsitswiderapplication.Therefore,itisnecessarytoimprovethewearresistanceofMoSi2.

Inrecentyears,theadditionofreinforcementsintothematrixhasbecomeaneffectivewaytoimprovethepropertiesofmaterials,andcompositematerialshavebeenwidelyused.La2O3andWSi2areexcellentceramicmaterials,whichcanimprovethethermalstabilityandwearresistanceofmaterialsbyaddingthemintothematrix.

Inthisstudy,MoSi2-basedcompositematerialswithdifferentamountsofLa2O3andWSi2werepreparedbyvacuuminductionmelting,hotisostaticpressingandheattreatment.TheeffectsofLa2O3andWSi2onthefrictionandwearpropertiesofMoSi2-basedcompositematerialswerestudied.

Experimentalmethods:

MoSi2-basedcompositematerialswerepreparedusingvacuuminductionmelting,hotisostaticpressingandheattreatment.ThecontentofLa2O3andWSi2inthecompositematerialswas0%,2%,4%,6%,8%,and10%bymassfraction.ThedensityandmicrostructureofthematerialswereobservedbyopticalmicroscopyandSEM.Thefrictionandwearpropertiesofthematerialswereevaluatedbyring-on-diskfrictiontester.

Resultsanddiscussion:

ThedensityoftheMoSi2-basedcompositematerialsgraduallyincreasedwiththeincreaseofthecontentofLa2O3andWSi2.TheadditionofLa2O3andWSi2changedthegrainsizeofMoSi2-basedcompositematerials,andthegrainsizedecreasedwiththeincreaseofthecontentofLa2O3andWSi2.

ThefrictioncoefficientoftheMoSi2-basedcompositematerialsdecreasedwiththeincreaseofthecontentofLa2O3andWSi2.WhenthecontentofLa2O3was4%,andthecontentofWSi2was10%,thefrictioncoefficientwasthelowest.ItwasfoundthattheadditionofLa2O3andWSi2couldreducethefrictioncoefficientofthematerial,whichmaybeduetotheformationofaprotectivefilmonthesurfaceofthematerialduringthefrictionprocess,whichreducesthefrictionandwear.

ThewearrateoftheMoSi2-basedcompositematerialsalsodecreasedwiththeincreaseofthecontentofLa2O3andWSi2.Thewearmechanismofthematerialwasmainlyadhesivewearandabrasivewear.WiththeincreaseofthecontentofLa2O3andWSi2,thewearmechanismwasgraduallytransformedfromadhesiveweartoabrasivewear.ThisisduetothefactthatthehardnessandstrengthofthematerialsincreasedafteraddingLa2O3andWSi2.

Conclusion:

Insummary,theadditionofLa2O3andWSi2cansignificantlyimprovethefrictionandwearpropertiesofMoSi2-basedcompositematerials.WhenthecontentofLa2O3was4%,andthecontentofWSi2was10%,thefrictioncoefficientwasthelowest,andthewearresistancewasthebest.Theimprovementofthefrictionandwearpropertiesofthematerialmaybeduetotheformationofaprotectivefilmonthesurfaceofthematerialduringthefrictionprocess,whichreducesthefrictionandwear.Furthermore,theadditionofLa2O3andWSi2intotheMoSi2matrixledtoarefinementofthemicrostructureandanincreaseinthematerial'sdensity.ThegrainsizeofthecompositematerialdecreasedwithincreasingLa2O3andWSi2content,whichcontributestotheimprovementofthewearresistancebyhinderingthecrackpropagationanddecreasingthedefectswithinthematerial.

ThewearresistanceoftheMoSi2-basedcompositematerialsshowedasignificantimprovementasLa2O3andWSi2contentwasincreased.Thedecreaseinwearratecanbeattributedtotheformationofceramic-basedprotectivelayersonthesurfacesofthecompositematerialduringthewearprocess,whichimprovedthematerial'sresistancetowear.Moreover,theabrasivewearmechanismgraduallybecomespreferableasthecontentofLa2O3andWSi2increases,whichcanbeexplainedbythefactthatLa2O3andWSi2possesshighhardnessandwearresistance.

Inconclusion,theresultsofthisstudydemonstratethattheadditionofLa2O3andWSi2intotheMoSi2matrixsignificantlyimprovesthefrictionandwearpropertiesofthecompositematerial.TheoptimumcontentofLa2O3andWSi2wasfoundtobe4%and10%,respectively,leadingtoanimprovementinboththetribologicalandmechanicalpropertiesofthecompositematerial.ThisresearchprovidesapotentialsolutionfortheenhancementofthewearresistanceofMoSi2-basedmaterials,andpavesthewayfortheirpotentialuseinhigh-temperatureapplications.Furthermore,theeffectoftheadditionofLa2O3andWSi2onthemechanicalpropertiesoftheMoSi2-basedcompositematerialswasalsoinvestigated.Theadditionofthesetwoelementsresultedinanincreaseinthehardness,compressivestrength,andfracturetoughnessofthematerial.ThiscanbeattributedtotheformationofasolidsolutionbetweenMoSi2andtheaddedelements,aswellastherefinementofthemicrostructurethatresultedinamorehomogenousdistributionofthereinforcingparticles.

TheimprovementinthemechanicalandtribologicalpropertiesoftheMoSi2-basedcompositematerialisofsignificantimportanceforthedevelopmentofmaterialsthatcanperformwellinhigh-temperatureandharshenvironments.Theseenvironmentsincludeaerospace,powergeneration,andnuclearindustries,wherehigh-performancematerialsareingreatdemand.TheenhancedpropertiesoftheMoSi2-basedcompositematerialcancontributetothedevelopmentofnewmaterialscapableofwithstandinghightemperatures,reducingmaintenancecosts,andincreasingtheoperatingefficiencyoftheseindustries.

Inaddition,theinvestigationofthewearmechanismsoftheMoSi2-basedcompositematerialsduringthefrictionandweartestsprovidedvaluableinsightsintotheunderlyingphysicalandchemicalprocessesthatoccurduringwear.Theresultssuggestedthattheformationofaceramic-basedprotectivelayerduringwearplayedacriticalroleinenhancingthewearresistanceofthecompositematerial.TheincreaseinhardnessandwearresistanceofthematerialcanbeattributedtothehighthermalstabilityandgoodoxidationresistanceofLa2O3andWSi2,bothofwhichcanenhancethematerial'sresistancetowear.

Inconclusion,theadditionofLa2O3andWSi2offersapromisingsolutionforimprovingthemechanicalandtribologicalpropertiesofMoSi2-basedmaterials.Theenhancedpropertiesofthecompositematerialmakeitaviablecandidateforuseinhigh-temperatureandharshenvironments,providingtheindustrywithapotentialsolutionforthedevelopmentofhigh-performancematerials.TheincorporationofLa2O3andWSi2hasbeenshowntohaveotherbeneficialeffectsontheMoSi2-basedcompositematerial.Forinstance,ithasbeenreportedthattheadditionofLa2O3canreducethesusceptibilityofMoSi2tooxidationbypromotingtheformationofaprotectiveoxidescaleonthesurfaceofthematerial.Thispropertymakesthematerialwell-suitedforhigh-temperatureapplicationswhereoxidationresistanceiscrucial.Additionally,WSi2hashighthermalandmechanicalstability,whichcontributestotheimprovedpropertiesofthecompositematerial,ultimatelyleadingtoitsincreasedwearresistance.

TheapplicationofMoSi2-basedcompositematerialsisnotonlylimitedtotheaerospace,powergeneration,andnuclearindustries,astheyhavealsoshownpotentialusesintheautomotive,chemicalprocessing,andmechanicalengineeringfields.Forexample,intheautomotiveindustry,thedevelopmentoflightweightanddurablematerialsisparticularlyessentialforthemanufacturingofenginesandexhaustsystems.MoSi2-basedcompositescanofferasolutionforsuchapplications,withtheirhigh-temperatureresistanceandwearresistancecapabilities,aswellastheiroverallmechanicalpropertiesthatmakethemsuperiorovertraditionalmaterialssuchassteelandaluminum.

Finally,theoptimizationofthemanufacturingprocessforMoSi2-basedcompositematerialsiscrucialtoensuretheirwidespreaduseindifferentindustries.Itisessentialtohaveacontrolledandreproduciblemethodofmanufacturingthecomposites,andnumerousmethodshavebeenproposedandinvestigated,suchaspowdermetallurgy,sparkplasmasintering,andhotpressing.Fine-tuningthemanufacturingprocesscanleadtofurtherimprovementsinthemechanicalandtribologicalpropertiesofthematerial,makingitanevenmoreviableoptionforvarioushigh-temperatureandharshenvironmentapplications.

Inconclusion,theresultsofresearchonMoSi2-basedcompositematerialsincorporatingLa2O3andWSi2haveshownthesignificantpotentialofthesematerialsfornumerousindustrialuses.Thesuperiormechanicalandtribologicalpropertiesofthesecompositematerialsmakethemaleadingcandidateforapplicationinhigh-temperatureandharshenvironments.Theincorporationofthesematerialscanprovideasolutionforthedevelopmentofhigh-performancematerialsinmultiplefields,withfurtheroptimizationofthemanufacturingprocesspromisingfurtherimprovements.AnotherpromisingcharacteristicofMoSi2-basedcompositematerialsistheirthermalconductivity.Thesematerialshaveahighthermalconductivityathightemperatures,allowingforefficientheattransferanddissipation,makingthemidealforuseinhigh-temperatureheatexchangersandfurnaces.Furthermore,theexcellentelectricalconductivityofthesecompositesmakesthemapotentialcandidatematerialforelectrodeapplicationsinelectrochemistryandotherindustries.

TheincorporationofdifferentreinforcementsintotheMoSi2-basedcompositematerialshasledtothedevelopmentofseveraladvancedvariantswithenhancedproperties.Forinstance,theadditionofcarbonfibershasledtothecreationoflightweightandhigh-strengthcompositeswithexcellenttoughnessandwearresistance.Similarly,theinclusionofceramicfibershasresultedincompositeswithexceptionalthermalshockresistanceandmechanicalstrength.

Inrecentyears,researchershavealsofocusedonexploringtheuseofothermaterials,suchasTiN,TiC,andZrC,asreinforcementstofurtherenhancethepropertiesofMoSi2-basedcomposites.ThesematerialsofferuniquepropertiesthatcancomplementthoseofMoSi2,makingthemevenmoreversatileandapplicableindifferentindustrialsettings.

ThedevelopmentandoptimizationofMoSi2-basedcompositematerialsholdgreatsignificanceinthequestformoreefficientanddurablematerialsforhigh-temperatureandharshenvironmentconditions.Thedemandforsuchmaterialsacrossvariousindustriesiscontinuallygrowing,andwithadvancementsinmanufacturingprocessesandtheincorporationofvariousreinforcements,thesecompositesarelikelytobecomeevenmoreprevalentinthecomingyears.Inadditiontotheirmechanicalandthermalproperties,MoSi2-basedcompositematerialsexhibitexcellentcorrosionandoxidationresistance.Thesepropertiesmakethemidealforuseinharshenvironments,suchaschemicalprocessingplants,whereexposuretoaggressivechemicalsandextremetemperaturesiscommon.

Theuniquecombinationofpropertiesexhibitedbythesecompositeshasalsoledtotheirapplicationintheaerospaceandautomotiveindustries.Forexample,intheaerospaceindustry,MoSi2-basedcompositeshavebeenusedtomanufacturecomponentssuchasturbinebladesandexhaustnozzlesduetotheirhigh-temperatureresistanceandlightweightnature.Similarly,intheautomotiveindustry,thesecompositeshavebeenusedforenginepartsthatrequirehigh-temperatureresistanceandmechanicalstrength.

AnotherpromisingapplicationforMoSi2-basedcompositesisinthefieldofrenewableenergy,particularlyinhigh-temperaturesolarenergyapplications.Thehighthermalconductivityandexcellentthermalstabilityofthesecompositesmakethemidealforuseinhigh-temperaturesolarreceivers,wheretheycanefficientlyabsorbandtransferheattogenerateelectricity.

Overall,MoSi2-basedcompositematerialshaveshownsignificantpotentialasaviablealternativetotraditionalmaterialsinvariousindustrialapplications.Thedevelopmentofnewandimprovedmanufacturingprocesses,coupledwiththeintegrationofnovelreinforcements,isexpectedtoleadtotheproductionofevenmoreadvancedandversatileMoSi2-basedcomposites,openingupnewpossibilitiesandopportunitiesfortheiruseindifferentindustries.Inadditiontotheapplicationsmentionedabove,MoSi2-basedcompositesarealsobeingexploredforuseinthefieldofmedicaldevicesandimplants.Theirbiocompatibilityandabilitytowithstandhigh-temperaturesterilizationmakethemsuitableforuseinmedicalapplicationsthatrequireahighdegreeofthermalstabilityandresistancetocorrosion.

Moreover,MoSi2-basedcompositesarebeingdevelopedforuseinvariousenergystorageapplications,suchasbatteriesandsupercapacitors.Theirhighelectricalconductivityandexceptionalmechanicalstrengthmakethemidealfordesigningadvancedenergystoragedevicesthataremorereliableandefficient.

AnotherapplicationbeingexploredistheuseofMoSi2-basedcompositesintheelectronicsindustry.Thesecompositeshavethepotentialtobeusedinhigh-temperatureelectronicdevices,suchastransistors,wheretheiruniquepropertiescanimproveperformanceandreliability.

Furthermore,MoSi2-basedcompositesarebeinginvestigatedforuseintheproductionofadvancedcoatingsandthinfilms.Thesecompositescanbeutilizedtocreatehighlydurableandcorrosion-resistantcoatings,suitableforuseinawiderangeofindustrialapplications.

Inconclusion,thepropertiesofMoSi2-basedcompositesmakethemhighlyversatileandsuitableforuseinvariousindustrialapplications.Theirexceptionalmechanical,thermal,andelectricalpropertiesprovidesuperiorperformanceanddurability,makingthemidealforuseinharshenvironmentswheretraditionalmaterialswouldfail.Withadvancementsinmanufacturingprocessesandtheintegrationofnovelreinforcements,thepotentialapplicationsofMoSi2-basedcompositeswillcontinuetoexpand,makingthemanattractiveoptionforvariousindustrialandcommercialapplications.AnotherpromisingapplicationforMoSi2-basedcompositesisintheaerospaceindustry.Thehigh-temperaturecapabilitiesofthesematerialsmakethemidealforuseinairplaneenginesandothercomponentsthatoperateatextremetemperatures.MoSi2-basedcompositescouldalsobeusedtodeveloplightweight,high-strengthcomponentsthatcanwithstandharshenvironments,suchasthoseencounteredduringspacetravel.

MoSi2-basedcompositesalsohavepotentialusesintheautomotiveindustry.Forexample,thesematerialscouldbeusedtodevelopcomponentsforhigh-performanceenginesoraslightweightstructuralcomponentsforelectricandhybridvehicles.Thehigh-temperaturestabilityandexcellentmechanicalpropertiesofMoSi2-basedcompositescouldalsohelpimprovethefuelefficiencyanddurabilityofautomobiles.

Intheconstructionindustry,MoSi2-basedcompositescouldbeusedtodevelophigh-strength,durablematerialsforuseinbuildingsandinfrastructure.Thesecompositescouldbeusedtocreatelightweight,high-strengthreinforcementmaterialsforconcreteorforstructuralcomponentsinbridgesandotherinfrastructureprojects.

Moreover,MoSi2-basedcompositeshavepotentialapplicationsinthechemicalindustry.Thehigh-temperaturestabilityandchemicalresistanceofthesematerialsmakethemidealforuseinchemicalprocessingandrefiningapplications.MoSi2-basedcompositescouldbeusedtodevelopcatalysts,refractorylinings,andothercomponentsusedinchemicalprocessingapplications.

Overall,theuniquepropertiesofMoSi2-basedcompositesmakethemhighlyversatileandsuitableforuseinawiderangeofindustrialapplications.Withadvancesinmanufacturingpro