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1、外文资料翻译附件：1、外文原文；2、外文资料翻译译文。1、外文原文（复印件）_-.SVAdvancedManufacturingTechnology4limitationsonacceptablefeedrates-determinedbytheabilityofthecuttingtitowithstandincreasedcuttingloadswithoutfracture.Increasingradialcuttingdepthsalsocouldincreaseremovalrates,althoughcuttingdepthisoftendeterminedbytheamounto
2、fstockremovalrequired.Asinthecaseofincreasedfeedrates,tllifedecreasedwithincreaseddepthofcut.Asexpected,atradeoffexistsbetweentllifeandremovalrate.,herearethreeforcesgeneratedineverymeulremovalprocess：tangentialforce,generatedbythepartrotation;radialforce,generatedbytheresistanceoftheworkpiecemateri
3、altodepthofcut；and,lastly,longitudinalforce,generatedbythefeedrateapplied.Theseforcesare30%to80%greaterthaninsoftmachiningprocesses.Forexample,whencomparingpreheat-treatedtoheat-treatedsteelwithahardnessof62HRC,thelongitudinalforceincreasesfrom30%to50%.Thetangentialforceincreases30%to40%,andtheradia
4、lforceincreasesfrom70%to(X)%.Therefore,themachinetoolmustbeabletohandletheincreasedcuttingforces,especiallyintheradialdirection.Cuttingolantcaninfluencethegenerationofwhitelayer.Becausewhitelayeristhoughttooccurastheresultofaphasetransformationonthesurface,cuttingclanimighthelpeliminatethermaldamage
5、bykeepingtheworkpiecesurfacecl.Somereportssaycuttingclanteliminateswhitelayer,butotherstudiesshowcIanthavingnoeffect.Toolconditionisalsobelievedtobeanimportantfactor,withnewtoolsproducingundamagedsurfaces,whilewhitelayerincreaseswithincreasing100Iwear.Ifhardturningistoreplacefinishgrindingoperations
6、,itmustbecapableofproducingsurfacefinishescomparabletothosegeneratedbygrinding.Unlikegrinding,wheresurfacefinishisdeterminedbythesize,shape,hardness,anddistributionofabrasivegrainsinthegrindingwheel,hard-turnedsurfacesarenominallydefinedbythegeometryofthecuttingprocess,primarilybythecuttingtsfeedrat
7、eandnoseradius.Forgrindingcylindricalapplications,boththewheelandtheworkpiecemustrotate.Moreover,thewheelrotatesrapidlywhiletheworkpiecerotatesslowly.Iftherotatingmembersareimperfectlyncentric,(hecombinationofimperfectionsandrtationalspeeddifferentialproduceslobing.AgeometricOUI-OCroUndPaaemonthewor
8、kpieceisproduced,whichcanaffecttheend-productperformance.Withhardturning,onhcotherhand,eithertheworkpieceorcuttingtoolisrotated,notboth.Therefbre,themachinedsurfacewillbeasaccurateasthemachinetoolspindleandthelongitudinaldirectionofthemachinetoolrelativetothecenterlineofthemachine.Anotherdisadvantag
9、ewithgrindingisthegenerationoftremendoussurfaceheatatthepointofcontactbetweenthegrindingwheelandtheworkpiece.Evenwhenfloodclantisproperlyapplied,workpiecesurfacestressrisersandheatcheckscanoccur,whichcanleadtoprematurefailureofthegroundpartinservice.Withhardturning,lessheatisgenerated,andifproperlya
10、ppliedttheheatthatisgeneratedwillbecarriedawaywiththeIMittIematerialremoved.Thus,thefinishedpartsareproducedwithoutstressrisersorheatchecks.AnothermajoradvantageofHPMisthatconventionalturningmachinescanbeusedwithworkpiecesashandas65HRCusingcommerciallyavailableceramicinserts.Savingsoccurintwoareas,p
11、rocessingandcapitalinvestment.Inprocessing,themachining,setup,andtoolchanginglimearesignificantlyreduced.Grindingwheelchanging,ontheotherhand,istime-consuming.Guardsmustberemoved,alongwiththespindlelockingnuts,thewornwheelmustbechanged,andthenewwheelbalancedanddressed.Wheelchangingcantakeasmuchas100
12、timeslongerthanchangingceramicinserts,whichrequireonlysimpleindexingorreplacementintheholder.Equipmentalsoislessexpensive.Aturningmachinecostssignificantlylessthanaproductiongrindertodocomparablework.Asalreadymentioned,setupiseasierandquicker.Turningmachinesalsoarcsimplerinnstnction(herearenorecipro
13、catingslidestowear,maintain,orreplace-foreasiermaintenance.However,thestrengthandrigidityofeverycomponentinthemachinemustbeadequatetohandletheadditionalcuttingforces.3.7.2HardMillingOnemachiningadvancementthathastakenholdoverthepastfewyearsishardmilling.Typicallymoldanddiemakerspertbnhardmillingtocu
14、tP-20,H-13andothertoolsteels.Thesematerialsrangeinhardnessfrom45to64HRCandaretraditionallyelectricaldischargemachined.Butnewtechnologiesmakehardmillingaviablealternative.Successfulhardmillingrequiresseveralcomponentstocometogether一themachinetool,tlholders,cuttingtls,CAD/CAMsystemandprocess*know-how.
15、”1. MachineFactorsThemachinetlisthemostSigniticantcomponent.Themostfundamentalaspectofthemachinetoolisthatitmustbedesignedforhardmillingandhavethesamecharacteristicsfoundinahigh-speedmachiningcenter.Themachine,sbasenstructionandindividualcomponents,suchasthedrivetrain,spindleandCNC,mustbecapableofha
16、ndling(hedemandsofhardmilling.Thebaseconstructionmustbeextremelyrigidandhaveahighdegreeofdampingabilities.Thesecharacteristicsarefoundinmachinetoolswithbasesconstructedfrompolymerconcrete.Thesemachinestypicallyhavesixto10timesthedampingcharacteristicsofmachineswithcastironbases.Additionally,polymerncretehasexcellentmechanicalandthermalcharacteristics.Themachinetool,sdrivetrainshouldinrporatedigitaldrivetechnologyforoptim
