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1、18MachiningandMachinabilityofAluminumAlloysV.Songmene,R.Khettabi,I.Zaghbani,J.Kouam,andA.DjebaraÉcoledetechnologiesupérieure(ÉTS),DepartmentofMechanicalEngineering,1100Notre-DameStreetWest,MontrealQuebecH3C1K3Canada1.IntroductionTheuseofmaterialswithlowspecificweightisaneffectiv
2、ewayofreducingtheweightofstructures.Aluminumalloysareamongthemostcommonlyusedlightweightmetallicmaterialsastheyofferanumberofdifferentinterestingmechanicalandthermalproperties.Inaddition,theyarerelativelyeasytoshapemetals,especiallyinmaterialremovalprocesses,suchasmachining.Infa
3、ct,aluminumalloysasaclassareconsideredasthefamilyofmaterialsofferingthehighestlevelsofmachinability,ascomparedtootherfamiliesoflightweightmetalssuchastitaniumandmagnesiumalloys.Thismachinabilityquantifiesthemachiningperformance,andmaybedefinedforaspecificapplicationbyvariouscrit
4、eria,suchastoollife,surfacefinish,chipevacuation,materialremovalrateandmachine-toolpower.Ithasbeenshownthatchemicalcomposition,structuraldefectsandalloyingelementssignificantlyinfluencemachinability[WKonigetal.,1983].Thus,withsimilarchemicalcompositions,themachinabilityofalloysc
5、anbeimprovedbydifferenttreatments.Heattreatments,whichincreasehardness,willreducethebuilt-upedge(BUE)tendencyduringmachining[M.Tashetal.,2006].Inthecaseofdrymachining,themajorproblemsencounteredaretheBUEatlowcuttingspeedsandstickingathighcuttingspeeds,hencetheneedforspecialtoolg
6、eometries[P.Royetal.,2008].IthasbeenshownthathighlevelsofMagnesium(Mg)increasethecuttingforcesatthesamelevelofhardness[M.Tashetal.,2006],whilealowpercentageofCopper(Cu)inaluminumalloy319decreasesthecuttingforce.Similarly,ithasbeenfoundthatheattreatmentof6061,especiallyaging,infl
7、uencestheforcesonlyatlowcuttingspeeds,whileathighspeeds,theinfluenceisnegligiblebecauseofthelowtemperatureriseseeninthecuttingzone[DemirHetal.,2008].Cuttingforceisjustoneamongseveralparameterstobeconsideredforafullassessmentofthemachinabilityofmetallicalloys,withtheothersbeingth
8、etoollife,thesurfacefinish,thecuttingenergyandt