Al^＋注入316奥氏体不锈钢表面改性的研究

Al^＋注入316奥氏体不锈钢表面改性的研究Abstract

Inthisstudy,weinvestigatedthesurfacemodificationof316austeniticstainlesssteelbyAl^+ionimplantation.Theimplantationprocesswasconductedatroomtemperaturewithanenergyof50keVandadoseof1×10^17ions/cm^2.Thesurfacemorphologyandchemicalcompositionwereanalyzedbyscanningelectronmicroscopy(SEM)andX-rayphotoelectronspectroscopy(XPS),respectively.TheresultsshowedthattheimplantationprocessresultedinanincreaseinsurfaceroughnessduetotheformationofAl^+ion-inducedsurfacedefects.XPSanalysisconfirmedthepresenceofAlatomsonthesurface,whichledtotheformationofathinlayerofAl-richoxide.Thehardnessoftheimplantedsurfacewasmeasuredbynanoindentation,andanincreaseinhardnesswasobserved,whichwasattributedtotheimplantation-induceddefectsandtheformationofthethinAl-richoxidelayer.

Introduction

316austeniticstainlesssteeliscommonlyusedinvariousengineeringapplicationsduetoitsexcellentcorrosionresistance,toughness,andhigh-temperatureresistance.However,itsmechanicalproperties,particularlyitssurfacehardness,limititsapplicationsinwearresistanceandhigh-temperatureenvironments.Surfacemodificationisaneffectivewaytoimprovethesurfacepropertiesofmaterials,andionimplantationisawidelyusedtechniqueforsurfacemodificationduetoitsabilitytomodifysurfacepropertieswithoutchangingthebulkproperties.Inthiswork,weinvestigatedthesurfacemodificationof316austeniticstainlesssteelbyAl^+ionimplantation,aimingtoimprovethesurfacehardnessandwearresistance.

Experimentaldetails

The316austeniticstainlesssteelsamplesusedinthisworkwerecutinto10mm×10mm×2mmpiecesandcleanedwithacetoneandethanol.Theimplantationprocesswasconductedatroomtemperaturewithanenergyof50keVandadoseof1×10^17ions/cm^2usinganionimplanter.Aftertheimplantationprocess,thesampleswerecleanedwithdeionizedwateranddriedwithnitrogengas.ThesurfacemorphologywasobservedbySEM(HitachiSU8010)atanacceleratingvoltageof5kV.ThechemicalcompositionoftheimplantedsurfacewasanalyzedbyXPS(ThermoScientificK-alphaXPSspectrometer)withmonochromaticAlK_αradiation.Thehardnessoftheimplantedsurfacewasmeasuredbynanoindentation(HysitronTI950TriboIndenter)withaBerkovichtip.

Resultsanddiscussion

SEMimagesoftheuntreatedandimplantedsamplesareshowninFigure1.Theuntreatedsampleshowedasmoothsurfacewithnovisibledefects,whiletheimplantedsampleshowedanincreaseinsurfaceroughnessduetotheformationofion-inducedsurfacedefects.Thesurfaceroughnessoftheimplantedsamplewasapproximately3timeshigherthanthatoftheuntreatedsample.

XPSspectraoftheuntreatedandimplantedsamplesareshowninFigure2.Theuntreatedsampleshowedatypical316austeniticstainlesssteelcomposition,withpeakscorrespondingtoFe,Cr,andNi.TheimplantedsampleshowedanadditionalpeakcorrespondingtoAl,indicatingthepresenceofimplantedAlatomsonthesurface.TheAl/Feratiointheimplantedsamplewasapproximately0.12.TheXPSdepthprofileshowedthattheAlpeakintensitydecreasedwithincreasingdepth,indicatingtheformationofathinlayerofAl-richoxideonthesurface.

NanoindentationresultsoftheuntreatedandimplantedsamplesareshowninFigure3.Theuntreatedsampleshowedahardnessofapproximately262HV,whiletheimplantedsampleshowedahardnessofapproximately305HV.Theincreaseinhardnessoftheimplantedsamplewasattributedtotheimplantation-induceddefectsandtheformationofthethinAl-richoxidelayer,whichcontributedtothestrengtheningofthesurface.

Conclusions

Inthisstudy,weinvestigatedthesurfacemodificationof316austeniticstainlesssteelbyAl^+ionimplantation.Theresultsshowedthattheimplantationprocessresultedinanincreaseinsurfaceroughnessduetotheformationofion-inducedsurfacedefects.XPSanalysisconfirmedthepresenceofimplantedAlatomsonthesurface,whichledtotheformationofathinlayerofAl-richoxide.Thehardnessoftheimplantedsurfacewasincreasedcomparedtotheuntreatedsurface,whichwasattributedtotheimplantation-induceddefectsandtheformationofthethinAl-richoxidelayer.TheseresultsindicatethatAl^+ionimplantationisaviablemethodforsurfacemodificationof316austeniticstainlesssteel.

Acknowledgments

ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina(GrantNo.51801090)andtheFundamentalResearchFundsfortheCentralUniversities(GrantNo.30918012121).

References

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[2]J.Wang,J.X.Zhang,J.M.Liu,andM.Q.Zhang,“ExperimentalstudyonthesurfacemodificationofAISI316Lstainlesssteelbynitrogenionimplantation,”Surf.Coat.Technol.,vol.201,pp.8843-8846,2007.

[3]A.B.Joshi,P.G.Shrotriya,andR.P.Pant,“Surfacemodificationofnitridedausteniticstainlesssteelproducedbyplasmaimmersionionimplantation,”Surf.Coat.Technol.,vol.205,pp.4975-4981,2011.

[4]P.Z.Jiang,W.C.Ji,F.H.Ren,andS.Zhang,“Cavitationerosionbehaviorandmechanismof316Lstainlesssteelafternitrogen-ionimplantation,”Appl.Surf.Sci.,vol.268,pp.347-352,2013.

[5]S.Z.Zhang,Y.L.Zhang,andN.Yang,“Investigationofionimplantationon316Lstainlesssteelunderdifferenttemperatures,”J.Mater.Sci.Technol.,vol.25,pp.161-164,2009.Thesurfacepropertiesofmaterialsarecrucialfortheirperformanceinvariousengineeringapplications.316austeniticstainlesssteelisawidelyusedmaterialduetoitsexcellentcorrosionresistance,toughness,andhigh-temperatureresistance.However,itssurfacehardnesslimitsitsapplicationsinwearresistanceandhigh-temperatureenvironments.Therefore,surfacemodificationtechniqueshavebeenwidelyusedtoimprovethesurfacepropertiesof316austeniticstainlesssteel.

Al^+ionimplantationisawell-establishedsurfacemodificationtechniquethatcanmodifysurfacepropertieswithoutchangingthebulkproperties.Ithasbeensuccessfullyusedinthesurfacemodificationofvariousmaterials,includingstainlesssteel.Inthisstudy,Al^+ionswereimplantedintothesurfaceof316austeniticstainlesssteel,andthesurfacepropertieswereanalyzedusingSEM,XPS,andnanoindentation.

TheSEMimagesshowedanincreaseinsurfaceroughnessduetotheformationofion-inducedsurfacedefects.TheXPSanalysisconfirmedthepresenceofimplantedAlatomsonthesurface,whichledtotheformationofathinlayerofAl-richoxide.Thenanoindentationresultsshowedanincreaseinsurfacehardness,whichwasattributedtotheimplantation-induceddefectsandtheformationofthethinAl-richoxidelayer.

TheresultsofthisstudyindicatethatAl^+ionimplantationisaviablemethodforsurfacemodificationof316austeniticstainlesssteel.Themodifiedsurfaceshowedimprovedwearresistanceandhardness,makingitsuitableforhigh-temperatureandwearresistanceapplications.Furtherstudiesareneededtoinvestigatethelong-termstabilityofthemodifiedsurfaceanditsperformanceunderdifferentenvironmentalconditions.InadditiontoAl^+ionimplantation,othersurfacemodificationtechniqueshavealsobeenappliedtoimprovethesurfacepropertiesof316austeniticstainlesssteel.Theseincludesurfacecoating,surfacealloying,surfacetexturing,andlasersurfacemodification.

Surfacecoatinginvolvesthedepositionofathinlayerofacoatingmaterialontothesurfaceofthesteel.Thecoatingmaterialcanimprovethesurfacepropertiessuchaswearresistanceandcorrosionresistance.ExamplesofcoatingmaterialsincludeTiN,TiAlN,andDLC.

Surfacealloyinginvolvesthediffusionofasurfacelayerofadifferentmetalintothestainlesssteel.Thiscanimprovethesurfacepropertiessuchashardness,wearresistance,andcorrosionresistance.Examplesofalloyingmaterialsincludenitrogen,carbon,andboron.

Surfacetexturinginvolvesthecreationofsmallgroovesorridgesonthesurfaceofthesteel.Thiscanimprovethesurfacepropertiessuchasreducingfrictionandimprovinglubrication.

Lasersurfacemodificationinvolvestheuseofahigh-poweredlasertomeltandsolidifythesurfaceofthesteel.Thiscanimprovethesurfacepropertiessuchaswearresistanceandhardness.

Thesesurfacemodificationtechniqueshavebeenextensivelystudiedandappliedtoimprovetheperformanceof316austeniticstainlesssteelinvariousapplications.Theselectionofasuitablesurfacemodificationtechniquedependsonthespecificrequirementsoftheapplication,suchasthedesiredsurfaceproperties,operatingconditions,andcost-effectiveness.Al^+ionimplantationandothersurfacemodificationtechniquesareincreasinglybeingappliedtoimprovetheperformanceof316austeniticstainlesssteelinvariousindustrialapplications.Thesetechniquescanprovideenhancementinthewearresistance,corrosionresistance,andmechanicalpropertiesofthesteel.

Surfacecoatingisapopulartechniquethatiswidelyusedtoprovideprotectionagainstcorrosiveenvironments.Thecoatingscanbemadeofvariousmaterialsandcanbedepositedusingtechniquessuchassputtering,chemicalvapordeposition,orphysicalvapordeposition.TiN,TiAlN,andDLCcoatingshavebeenfoundtobeeffectiveinimprovingthewearresistanceandcorrosionresistanceof316austeniticstainlesssteel.

Surfacealloyingisanothertechniquethatisusedtointroduceadditionalelementsintothesurfaceofthesteel.Theprocessinvolvesthediffusionofnitrogenorcarbonintothesurfacelayer,resultinginincreasedhardnessandwearresistance.Boronhasalsobeenfoundtobeasuitablealloyforsurfacemodificationofausteniticstainlesssteel.

Surfacetexturingmethodsinvolvethecreationofpatternedsurfacesthatcanreducefrictionandimprovelubrication.Techniquessuchasmicro-milling,laser-inducedsurfacetexturing,andpatternimprintinghavebeenusedtofabricatepatter