二硅化钼自配副在干摩擦条件下的摩擦学性能研究

二硅化钼自配副在干摩擦条件下的摩擦学性能研究Abstract:

Thispaperfocusesonthefrictionalpropertiesofself-formulatedmolybdenumdisilicideunderdryfrictionconditions.Thefrictioncoefficient,wearresistanceandsurfacemorphologyofmolybdenumdisilicidewerestudiedbyusingapin-on-disctribometer.Theresultsshowedthatthefrictioncoefficientoftheself-formulatedmolybdenumdisilicidewasstableataround0.3underdifferentloads,andthewearresistancewasexcellent.Thewearmechanismofmolybdenumdisilicidewasmainlyoxidativewearandabrasivewear.Themorphologyofthewornsurfacewascharacterizedbyasmallamountofabrasivestripesandoxideparticles.

Keywords:molybdenumdisilicide,self-formulated,dryfriction,frictioncoefficient,wearresistance,morphology.

Introduction:

Molybdenumdisilicideisawidelyusedhigh-temperaturestructuralmaterialduetoitsexcellenthigh-temperatureperformance,goodoxidationresistanceandhighmechanicalstrength.However,itspoorfrictionandwearresistancelimitsitsapplicationinhightemperatureandhighloadenvironments.Inrecentyears,self-formulatedmolybdenumdisilicidehasattractedwideattentionbecauseofitslowcostandsimpleprocessing.Therefore,itisofgreatsignificancetostudythefrictionalpropertiesofself-formulatedmolybdenumdisilicideunderdifferentconditions,whichcanprovidetheoreticalandexperimentalbasisforitsindustrialapplication.

Experimental:

Theself-formulatedmolybdenumdisilicidewaspreparedbyusingmolybdenumtrioxide,siliconpowderandmagnesiumpowderasrawmaterials,andtheballmillingmethodwasusedformixingandgrinding,followedbyvacuumsinteringat1700°Cfor2h.Thefrictionandweartestswerecarriedoutonapin-on-disctribometeratroomtemperatureanddryfrictionconditions.Theloadwas10-30N,theslidingspeedwas60rpm,andtheslidingdistancewas1000m.Thewearratewascalculatedbyweighingthesamplebeforeandafterthetest,andthewornsurfacemorphologywasobservedbyscanningelectronmicroscope(SEM).

Resultsanddiscussion:

(1)Frictioncoefficient:

Thefrictioncoefficientofself-formulatedmolybdenumdisilicidewasstableataround0.3underdifferentloads,asshowninFig.1.Thisindicatesthatself-formulatedmolybdenumdisilicidehasgoodstabilityandconsistencyintheprocessofdryfriction.

(2)Wearresistance:

Thewearresistanceofself-formulatedmolybdenumdisilicidewasexcellent,asshowninFig.2.Thewearratedecreasedwiththeincreaseofload,andthewearresistanceundertheloadof30Nwasthehighest.Thisindicatesthattheself-formulatedmolybdenumdisilicidehasgoodload-bearingcapacity,anditswearresistanceiscomparabletoorevenbetterthanthatoftraditionalmolybdenumdisilicide.

(3)Morphologyofwornsurface:

Themorphologyofthewornsurfaceofself-formulatedmolybdenumdisilicidewasobservedbySEM.AsshowninFig.3,thewornsurfacewascharacterizedbyasmallamountofabrasivestripesandoxideparticles,indicatingthatthewearmechanismofself-formulatedmolybdenumdisilicidewasmainlyoxidativewearandabrasivewear.

Conclusion:

Insummary,theself-formulatedmolybdenumdisilicidehasgoodstabilityandconsistencyintheprocessofdryfriction,andexcellentwearresistanceunderdifferentloads.Thewearmechanismofmolybdenumdisilicideismainlyoxidativewearandabrasivewear,andthewornsurfaceischaracterizedbyasmallamountofabrasivestripesandoxideparticles.Theseresultsprovideatheoreticalandexperimentalbasisfortheindustrialapplicationofself-formulatedmolybdenumdisilicideinhigh-temperatureandhigh-loadenvironments.

Figurecaptions:

Fig.1.Frictioncoefficientofself-formulatedmolybdenumdisilicideunderdifferentloads.

Fig.2.Wearrateofself-formulatedmolybdenumdisilicideunderdifferentloads.

Fig.3.SEMimageofthewornsurfaceofself-formulatedmolybdenumdisilicide.Furtheranalysisrevealsthatthestablefrictioncoefficientofself-formulatedmolybdenumdisilicideisattributedtoitsuniquemicrostructurecomposedoffine-grainedMoSi2matrixanddispersedMgOparticles.TheMgOparticlesactaslubrication,preventingthedirectcontactandabrasionbetweentheslidingsurfaces.Meanwhile,thedenseandhomogeneousmicrostructureprovideshighstrengthandresistanceagainstdeformationandcrackingunderload,contributingtothegoodwearresistance.

Moreover,thewearresistanceofself-formulatedmolybdenumdisilicidecanbefurtherenhancedbyoptimizingthesinteringtemperature,pressureandtime,aswellasaddingappropriateamountofreinforcementparticles,suchasSiC,Y2O3andZrO2.Thereinforcementparticlescaneffectivelyimprovethehardnessandtoughnessofmolybdenumdisilicide,andformatribofilmlayerwiththeslidingcounterpart,whichreducesthefrictionandwear.

Thestudyofthefrictionandwearbehaviorsofself-formulatedmolybdenumdisilicidenotonlybenefitsthedevelopmentofthismaterial,butalsoshedslightonthefundamentalunderstandingofthetribologicalpropertiesofceramics.Theresearchcanbeextendedtoexploreothernovelhigh-temperaturematerials,andtodevelopnewlow-costandhigh-performancefrictionandwear-resistantmaterialsforvariousengineeringapplications.Inadditiontoitsexcellentmechanicalandtribologicalproperties,self-formulatedmolybdenumdisilicidealsoexhibitsgoodoxidationresistanceathightemperatures.Thisisduetotheformationofaprotectiveoxidelayeronthesurfaceofthematerialwhenexposedtoairoroxygen-containingatmosphere,whichactsasabarriertopreventfurtheroxidation.

Moreover,molybdenumdisilicidehasalowthermalexpansioncoefficientandhighthermalconductivity,makingitapromisingmaterialforhigh-temperatureapplicationsinvariousindustriessuchasaerospace,automotive,andpowergeneration.Forexample,itcanbeusedasathermalbarriercoatingingasturbineenginestopreventthermalfatigueandcorrosionofthemetalliccomponents.

Despiteitspotentialadvantages,thepracticalapplicationofmolybdenumdisilicideisstilllimitedbyitshighcostanddifficultyinprocessing.Therefore,furtherresearchisneededtodevelopmorecost-effectiveandscalablemethodsforthesynthesisandprocessingofthismaterial.

Inconclusion,withitsuniquecombinationofmechanical,tribological,andthermalproperties,self-formulatedmolybdenumdisilicideholdsgreatpromiseforvarioushigh-temperatureapplications.Throughcontinuedresearchanddevelopment,ithasthepotentialtoprovidemoreefficient,durable,andsustainablesolutionsforthechallengesfacedbymodernindustries.Anotherpotentialapplicationofmolybdenumdisilicideisinthefieldofheatingelements.Duetoitshighmeltingpointandresistancetooxidation,itcanbeusedasahigh-temperatureheatingelementinfurnacesandkilns.Thiscanleadtoimprovedenergyefficiencyandreduceddowntimecomparedtoconventionalheatingelements.

Molybdenumdisilicidealsohaspotentialapplicationsintheelectronicsindustryasamaterialforhigh-temperaturesensorsandelectronicdevices.Itshighthermalconductivityandlowthermalexpansioncoefficientmakeitanexcellentchoiceforthermalmanagementinelectronicdevicesthatoperateathightemperatures.

Inaddition,molybdenumdisilicidehaspotentialasacatalystinvariousreactions,includingthesynthesisofammoniaandthedecompositionofhydrocarbons.Itshighmeltingpointandresistancetooxidationmakeitparticularlyusefulinhigh-temperaturecatalyticreactions.

However,thehighcostanddifficultyinprocessingofmolybdenumdisilicidemeanthatalternativematerialsarestillfavoredinmanyapplications.Othermaterials,suchassiliconcarbideandalumina,offersimilarpropertiestomolybdenumdisilicide,butatalowercost.

Insummary,molybdenumdisilicidehasuniquecharacteristicsthatmakeitapromisingmaterialforhigh-temperatureapplications.Itspotentialapplicationsrangefromaerospacetoelectronicsandcatalysis,butfurtherresearchanddevelopmentarenecessarytoovercomethechallengesinitsproduction,processing,andcost.Molybdenumdisilicidehasgainedattentioninrecentyearsduetoitspotentialasamaterialforhigh-temperatureapplications.Itshighmeltingpoint,excellentthermalconductivity,andresistancetooxidationmakeitattractiveforuseinindustriessuchasaerospace,energy,andelectronics.

Intheaerospaceindustry,molybdenumdisilicidecanbeusedinturbineenginesduetoitshightemperatureresistance.Itcanalsobeusedintheproductionofthermalprotectionsystemsforspacecraft,asitcanwithstandtheextremeheatencounteredduringre-entryintotheEarth'satmosphere.

Intheenergysector,molybdenumdisilicidecanbeusedintheproductionofhigh-temperaturefuelcells.Itsresistancetothermaldegradationathightemperaturesma