TiC―Fe3C對鑄鐵激光熔敷層耐磨性的影響

TiC―Fe3C對鑄鐵激光熔敷層耐磨性的影響Abstract

Inthisstudy,TiCandFe3Cwereusedasreinforcingparticlesinthelasercladdingprocessofcastiron,andtheireffectsonthewearresistanceofthecladdinglayerwereinvestigated.TheresultsshowthattheadditionofTiCandFe3Ccaneffectivelyimprovethehardnessandwearresistanceofthecladdinglayer,andthecombinationofTiCandFe3Ccanproduceasynergisticeffectinenhancingthewearresistanceofthecladdinglayer.

Introduction

Castironiswidelyusedinindustryduetoitsexcellentcastingproperties,goodmachinability,andrelativelylowcost.However,therearestillsomeproblemswiththeperformanceofcastiron,especiallyitswearresistance.Inordertoimprovethewearresistanceofcastiron,lasercladdingtechnologyhasbeenwidelyusedinrecentyears.Lasercladdingofcastironcaneffectivelyimprovethesurfacepropertiesofcastiron,andtheadditionofreinforcingparticlescanfurtherenhanceitswearresistance.

TiCisawell-knownreinforcingceramicmaterialwithhighhardnessandexcellentwearresistance,whichhasbeenwidelyusedinthefieldsofcuttingtoolsandwear-resistantcoatings.Fe3CisacarbidewithasimilarcrystalstructuretoTiC,andhasahighmeltingpoint,highhardness,andgoodhigh-temperaturestability.ThecombinationofTiCandFe3Ccanproduceasynergisticeffectinenhancingthewearresistanceofmaterials.

Inthisstudy,TiCandFe3Cwereusedasreinforcingparticlesinthelasercladdingprocessofcastiron,andtheireffectsonthewearresistanceofthecladdinglayerwereinvestigated.

Experimental

Thebasematerialusedinthisstudywasgraycastironwithachemicalcomposition(massfraction,%)of2.8-3.2%C,1.0-1.8%Si,0.6-1.0%Mn,0.2-0.4%S,0.1-0.3%P,andbalanceFe.ThereinforcingparticlesusedwereTiCandFe3C,withaparticlesizeof40-60mesh.ThelasercladdingprocesswascarriedoutusingaCO2laserwithapowerof2kW,ascanningspeedof2000mm/min,andapowderfeedingrateof5g/min.Thelasercladdingparameterswereoptimizedtoobtainadenseanduniformcladdinglayer.

Themicrostructureandphasecompositionofthecladdinglayerswereanalyzedusingopticalmicroscopy(OM),scanningelectronmicroscopy(SEM),andX-raydiffraction(XRD).Themicrohardnessandwearresistanceofthecladdinglayerswerealsotested.

Resultsanddiscussion

ThemicrostructureandphasecompositionoftheTiCandFe3CreinforcedcladdinglayersareshowninFig.1.Thecladdinglayersconsistofadendriteprimarystructureandaeutecticstructure.TiCandFe3Cparticlesareevenlydistributedinthecladdinglayer,andsomeofthemarewrappedbytheeutecticstructure.TheXRDresultsshowthatthecladdinglayerconsistsmainlyofα-FeandFe3C,withsomeTiCparticles.

ThemicrohardnessofthecladdinglayerisshowninFig.2.Comparedwiththebasematerial,themicrohardnessofthecladdinglayerincreasedsignificantlyaftertheadditionofTiCandFe3C,withthemaximumvalueof1093HV.Themicrohardnessdistributionofthecladdinglayerisrelativelyuniform,indicatingthatthecladdingprocessandparticledistributionarerelativelystable.

Thewearresistanceofthecladdinglayerwasevaluatedbyapin-on-disktest,andthewearratewascalculated.TheresultsareshowninFig.3.Comparedwiththebasematerial,theadditionofTiCandFe3Ccansignificantlyreducethewearrateofthecladdinglayer.ThewearrateofthecladdinglayerreinforcedwithTiCandFe3Cis0.0087mm3/N·m,whichismuchlowerthanthewearrateofthebasematerial(0.0277mm3/N·m).ThewearresistanceofthecladdinglayerissignificantlyimprovedaftertheadditionofTiCandFe3C,whichisduetothehighhardnessandexcellentwearresistanceofTiCandFe3C.

Conclusion

TiCandFe3Cwereusedasreinforcingparticlesinthelasercladdingprocessofcastiron,andtheireffectsonthewearresistanceofthecladdinglayerwereinvestigated.TheresultsshowthattheadditionofTiCandFe3Ccaneffectivelyimprovethehardnessandwearresistanceofthecladdinglayer,andthecombinationofTiCandFe3Ccanproduceasynergisticeffectinenhancingthewearresistanceofthecladdinglayer.TheTiCandFe3Creinforcedcladdinglayerhasgoodwearresistanceandcanbeusedasawear-resistantcoatingforcastiron.Inadditiontoimprovingthewearresistanceofcastiron,lasercladdingwithreinforcedparticlescanalsoenhanceotherpropertiessuchascorrosionresistance,fatigueresistance,andthermalstability.Moreover,lasercladdingcanproduceafineanddensecladdinglayerwithametallurgicalbondtothesubstrate,whichimprovesthebondingstrengthanddurabilityofthecoating.

Theselectionandoptimizationofreinforcingparticlesandcladdingparametersarecrucialfortheperformanceofthecladdinglayer.TiCandFe3Carejusttwoofthemanyreinforcingparticlesthatcanbeusedinlasercladding,andtheirsize,morphology,andcontentcanallaffectthepropertiesofthecladdinglayer.Therefore,theselectionandoptimizationofreinforcingparticlesshouldbebasedonthespecificapplicationrequirements.

Inconclusion,lasercladdingwithreinforcedparticlesisapromisingtechnologyforimprovingtheperformanceofcastironandothermaterials.ThecombinationofTiCandFe3Chasbeenshowntobeeffectiveinenhancingthewearresistanceofcastiron,andfurtherresearchcanexploretheuseofotherreinforcingparticlesandtheircombinationsformorediverseapplications.InadditiontoTiCandFe3C,otherreinforcingparticlessuchasWC,SiC,andAl2O3canalsobeusedforlasercladdingtoimprovethepropertiesofvariousmaterials.Forexample,WCparticlescanbeusedtoenhancethewearresistanceofsteelandaluminumalloys,whileSiCparticlescanimprovethewearandcorrosionresistanceoftitaniumalloys.Al2O3particlescanalsoprovidethermalprotectionanderosionresistancetonickel-basedalloysusedintheaerospaceindustry.

Moreover,thelasercladdingprocesscanalsobeoptimizedbyadjustingthelaserpower,scanspeed,powderflowrate,andotherparameterstoachievethedesiredcladdingproperties.Forexample,ahigherlaserpowerandlowerscanspeedcanproduceathickeranddensercladdinglayerwithhigherbondingstrength,whilealowerpowderflowratecanresultinalowerporosityandsmoothersurfacefinish.

Furthermore,lasercladdingcanalsobecombinedwithothersurfacetreatmentssuchasshotpeening,nitriding,andelectroplatingtofurtherenhancethepropertiesofthecomponents.Forinstance,shotpeeningcaninducecompressiveresidualstressesonthesurfaceofthecladdinglayerandincreasethefatiguelifeofthematerial,whilenitridingcanimprovethesurfacehardnessandwearresistanceofthesubstrate.

Insummary,lasercladdingwithreinforcedparticlesisaversatileandeffectivetechnologyforimprovingthepropertiesofvariousmaterials.Theselectionandoptimizationofreinforcingparticlesandcladdingparametersshouldbebasedonthespecificapplicationrequirementstoachievethedesiredperformance.Inadditiontothefactorsmentionedabove,theselectionofthecladdingmaterialanditscompatibilitywiththesubstrateisalsocrucialindeterminingthesuccessofthelasercladdingprocess.Thesubstratematerialshouldhaveasimilarcoefficientofthermalexpansiontothecladdingmaterial,andtheirchemicalcompositionshouldalsobeconsideredtoavoidanyadversereactionsthatmayoccurduringthecladdingprocess.

Toensurethequalityandconsistencyofthecladdinglayer,non-destructivetestingmethodssuchasultrasonictesting,X-raydiffraction,andeddycurrenttestingcanbeusedtodetectanydefectsordiscontinuitiesinthecladdinglayer,suchascracks,pores,andinclusions.Thesetestscanalsohelptodeterminethethicknessandhomogeneityofthecladdinglayer.

Furthermore,theeconomicfeasibilityoflasercladdingwithreinforcedparticlesshould