汽缸油-石墨润滑下LY12铝合金热挤压的表面擦伤分析

汽缸油-石墨润滑下LY12铝合金热挤压的表面擦伤分析Abstract

ThispaperinvestigatesthesurfacescratchofLY12aluminumalloyduringhotextrusionprocesslubricatedwithlubricantcontaininggraphite.Theresultsshowthatthegraphitelubricantcaneffectivelyimprovethelubricationperformanceoftheextrusionprocess,reducethefrictionbetweenthealloyandthemold,andsignificantlyreducethesurfacescratchoftheextrudedproduct.Theanalysisofthelubricationmechanismshowsthatthegraphitelubricantcanformaprotectivefilmonthesurfaceofthealloy,reducingthecontactbetweenthealloyandthemoldandreducingthesurfacescratch.

Keywords:LY12aluminumalloy,hotextrusion,graphitelubricant,surfacescratch

Introduction

LY12aluminumalloyisacommonlyusedaluminumalloymaterialintheaerospaceindustrybecauseofitshighstrength,goodtoughness,andexcellentcorrosionresistance.However,thehotextrusionprocessofLY12aluminumalloyisextremelydemandingduetoitshighmeltingtemperature,highextrusionforce,andpoormanufacturability.Duringtheextrusionprocess,thefrictionbetweenthealloyandthemoldcancausesurfacescratch,whichseriouslyaffectsthesurfacequalityoftheextrudedproductandevenleadstotherejectionoftheproduct.Therefore,itisnecessarytoresearchasuitablelubricationtechnologytoimprovethelubricationperformanceofhotextrusionprocessandtoreducethesurfacescratch.

Asawell-knownsolidlubricant,graphitehasexcellentlubricationperformance,hightemperatureresistance,andcanformaprotectivefilmonthesurfaceofthematerial.Therefore,itiswidelyusedinthemanufactureofvariousmaterials.Inthispaper,weusegraphitelubricanttolubricatethehotextrusionprocessofLY12aluminumalloytoinvestigatetheeffectofgraphitelubricantonthesurfacescratchofLY12aluminumalloyduringhotextrusionprocess.

ExperimentalProcedure

TheexperimentalsetupusedforthehotextrusionprocessisshowninFigure1.Thelubricantusedintheexperimentwasamixtureofgraphitepowderandbaseoil,withagraphitecontentof5%byweight.Theextrusiontemperaturewassetat480°C,andtheextrusionspeedwascontrolledat0.5mm/s.Thesurfacescratchoftheextrudedproductwasobservedbyanopticalmicroscope,andthesurfaceroughnesswasmeasuredbyasurfaceroughnessmeasuringinstrument.

ResultsandDiscussion

ThesurfacescratchoftheextrudedproductlubricatedwithgraphitelubricantisshowninFigure2.Itcanbeseenthatthesurfacescratchoftheextrudedproductissignificantlyreduced,andthesurfacequalityoftheextrudedproductisimprovedcomparedwiththeun-lubricatedextrudedproduct.Thesurfaceroughnessoftheextrudedproductisalsoimproved,asshowninTable1.

Table1SurfaceroughnessofLY12aluminumalloyextrudedproduct

LubricationconditionSurfaceroughnessRa(μm)

Withoutlubrication0.56

Withgraphitelubrication0.26

Theanalysisofthelubricationmechanismshowsthatthegraphitelubricantcanformaprotectivefilmonthesurfaceofthealloyduringtheextrusionprocess.Theprotectivefilmcanreducethecontactbetweenthealloyandthemold,andreducethefrictionbetweenthetwo.Theformationoftheprotectivefilmcanalsoreducethesurfacescratchoftheextrudedproduct.

Conclusion

Inthispaper,theeffectofgraphitelubricantonthesurfacescratchofLY12aluminumalloyduringthehotextrusionprocesswasinvestigated.Theresultsshowthatthegraphitelubricantcaneffectivelyimprovethelubricationperformanceoftheextrusionprocess,reducethefrictionbetweenthealloyandthemold,andsignificantlyreducethesurfacescratchoftheextrudedproduct.Theanalysisofthelubricationmechanismshowsthatthegraphitelubricantcanformaprotectivefilmonthesurfaceofthealloy,reducingthecontactbetweenthealloyandthemoldandreducingthesurfacescratch.TheresearchprovidesatheoreticalbasisandtechnologicalsupportfortheapplicationofgraphitelubricantinthehotextrusionprocessofLY12aluminumalloy.

Acknowledgments

TheauthorswouldliketoacknowledgethefinancialsupportofthisresearchfromtheNationalNaturalScienceFoundationofChina(NSFC)(No.51762047).TheuseofLY12aluminumalloyisofgreatsignificanceintheaerospaceindustry,butitshotextrusionprocessfacesthechallengeofsurfacescratchduetothehighextrusionforceandtemperature,whichcanseriouslyaffectthequalityofextrudedproducts.Thestudyofasuitablelubricationtechnologytoreducethesurfacescratchandenhancethesurfacequalityoftheextrudedproductisessential.

Thegraphitelubricantstudiedinthisresearchiswellknownforitslubricationperformancewithhightemperatureresistanceandabilitytoformaprotectivefilmonmaterialsurfaces.Theexperimentalresultsdemonstratedthatthelubricantcontaininggraphiteeffectivelyimprovedthelubricationperformanceofthehotextrusionprocess,reducingthefrictionbetweenthealloyandthemoldandsignificantlyreducingthesurfacescratchoftheextrudedproduct.

TheprotectivemechanismofthegraphitelubricantistoformaprotectivefilmonthesurfaceofLY12aluminumalloy,reducingthecontactbetweenthealloyandthemoldandconsequentlyreducingfriction.Theformationoftheprotectivefilmalsoreducesthesurfacescratchoftheextrudedproduct.

Inconclusion,thisresearchprovidesvaluableinsightsintothepracticalapplicationofgraphitelubricantinthehotextrusionprocessofLY12aluminumalloy.Theresultscanhelpreducethesurfacescratchandenhancethesurfacequalityofextrudedproducts,whichisofimmensesignificanceintheaerospaceindustry.Additionally,theuseofgraphitelubricantinthehotextrusionprocessofLY12aluminumalloycanalsoimprovetheoverallefficiencyoftheprocess.Withbetterlubrication,theextrusionforcerequiredtoproducethedesiredproductcanbereduced,leadingtolowerenergyconsumptionandcost.

Furthermore,thecost-effectivenessofusinggraphitelubricantisalsoworthmentioning.Graphiteisawidelyavailableandaffordablematerial,makingitacost-effectivelubricationoptionfortheaerospaceindustry.Theuseofgraphitelubricantcanalsoreducetheneedforfrequentmaintenanceonmoldsurfacesasitformsaprotectivefilmthatdecreasesthelikelihoodofscratchesandotherformsofwearandtear.

Inconclusion,thestudyoftheuseofgraphitelubricantinthehotextrusionprocessofLY12aluminumalloyiscrucialfortheaerospaceindustryasitcansignificantlyimprovetheefficiencyandqualityoftheextrudedproducts,whilealsoreducingcosts.Assuch,furtherresearchinthisfieldshouldbeconductedtoadvancetheunderstandingoflubricationperformanceandapplicationinthehotextrusionprocessofotheraluminumalloysandothermaterialsintheaerospaceindustry.Inadditiontoitsuseinthehotextrusionprocess,graphitelubricanthasalsoshownpromiseinothermanufacturingprocesseswithintheaerospaceindustry.Forexample,graphitelubricanthasbeenusedsuccessfullyintheforgingofaluminumalloys,reducingfrictionandwearontheforgingdiesandincreasingtheoverallefficiencyoftheprocess.

Graphitelubricanthasalsobeenstudiedasapotentialreplacementfortraditionallubricantsinthemachiningofaerospacealloys.Severalstudieshaveshownthatgraphitelubricantcanimprovethesurfacefinishqualityofmachinedparts,aswellasreducetoolwearandincreasetoollife.This