先进制造技术----中英文翻译.docx

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,althoughcuttingdepthisoftendeterminedbytheamountofstockremovalrequired.Asinthecaseofincreasedfeedrates,tllifedecreasedwithincreaseddepthofcut.Asexpected,atradeoffexistsbetweentllifeandremovalrate.,herearethreeforcesgeneratedineverymeulremovalprocess：tangentialforce,generatedbythepartrotation;radialforce,generatedbytheresistanceoftheworkpiecematerialtodepthofcut；and,lastly,longitudinalforce,generatedbythefeedrateapplied.Theseforcesare30%to80%greaterthanin"soft"machiningprocesses.Forexample,whencomparingpreheat-treatedtoheat-treatedsteelwithahardnessof62HRC,thelongitudinalforceincreasesfrom30%to50%.Thetangentialforceincreases30%to40%,andtheradialforceincreasesfrom70%to(X)%.Therefore,themachinetoolmustbeabletohandletheincreasedcuttingforces,especiallyintheradialdirection.Cuttingolantcaninfluencethegenerationofwhitelayer.Becausewhitelayeristhoughttooccurastheresultofaphasetransformationonthesurface,cuttingclanimighthelpeliminatethermaldamagebykeepingtheworkpiecesurfacecl.Somereportssaycuttingclanteliminateswhitelayer,butotherstudiesshowcIanthavingnoeffect.Toolconditionisalsobelievedtobeanimportantfactor,withnewtoolsproducingundamagedsurfaces,whilewhitelayerincreaseswithincreasing100Iwear.Ifhardturningistoreplacefinishgrindingoperations,itmustbecapableofproducingsurfacefinishescomparabletothosegeneratedbygrinding.Unlikegrinding,wheresurfacefinishisdeterminedbythesize,shape,hardness,anddistributionofabrasivegrainsinthegrindingwheel,hard-turnedsurfacesarenominallydefinedbythegeometryofthecuttingprocess,primarilybythecuttingtsfeedrateandnoseradius.Forgrindingcylindricalapplications,boththewheelandtheworkpiecemustrotate.Moreover,thewheelrotatesrapidlywhiletheworkpiecerotatesslowly.Iftherotatingmembersareimperfectlyncentric,(hecombinationofimperfectionsandrtationalspeeddifferentialproduceslobing.AgeometricOUI-OCroUndPaaemontheworkpieceisproduced,whichcanaffecttheend-productperformance.Withhardturning,onhcotherhand,eithertheworkpieceorcuttingtoolisrotated,notboth.Therefbre,themachinedsurfacewillbeasaccurateasthemachinetoolspindleandthelongitudinaldirectionofthemachinetoolrelativetothecenterlineofthemachine.Anotherdisadvantagewithgrindingisthegenerationoftremendoussurfaceheatatthepointofcontactbetweenthegrindingwheelandtheworkpiece.Evenwhenfloodclantisproperlyapplied,workpiecesurfacestressrisersandheatcheckscanoccur,whichcanleadtoprematurefailureofthegroundpartinservice.Withhardturning,lessheatisgenerated,andifproperlyappliedttheheatthatisgeneratedwillbecarriedawaywiththeIMittIematerialremoved.Thus,thefinishedpartsareproducedwithoutstressrisersorheatchecks.AnothermajoradvantageofHPMisthatconventionalturningmachinescanbeusedwithworkpiecesashandas65HRCusingcommerciallyavailableceramicinserts.Savingsoccurintwoareas,processingandcapitalinvestment.Inprocessing,themachining,setup,andtoolchanginglimearesignificantlyreduced.Grindingwheelchanging,ontheotherhand,istime-consuming.Guardsmustberemoved,alongwiththespindlelockingnuts,thewornwheelmustbechanged,andthenewwheelbalancedanddressed.Wheelchangingcantakeasmuchas100timeslongerthanchangingceramicinserts,whichrequireonlysimpleindexingorreplacementintheholder.Equipmentalsoislessexpensive.Aturningmachinecostssignificantlylessthanaproductiongrindertodocomparablework.Asalreadymentioned,setupiseasierandquicker.Turningmachinesalsoarcsimplerinnstnction(herearenoreciprocatingslidestowear,maintain,orreplace-foreasiermaintenance.However,thestrengthandrigidityofeverycomponentinthemachinemustbeadequatetohandletheadditionalcuttingforces.3.7.2HardMillingOnemachiningadvancementthathastakenholdoverthepastfewyearsishardmilling.TypicallymoldanddiemakerspertbnhardmillingtocutP-20,H-13andothertoolsteels.Thesematerialsrangeinhardnessfrom45to64HRCandaretraditionallyelectricaldischargemachined.Butnewtechnologiesmakehardmillingaviablealternative.Successfulhardmillingrequiresseveralcomponentstocometogether一themachinetool,tlholders,cuttingtls,CAD/CAMsystemandprocess*know-how.”1. MachineFactorsThemachinetlisthemostSigniticantcomponent.Themostfundamentalaspectofthemachinetoolisthatitmustbedesignedforhardmillingandhavethesamecharacteristicsfoundinahigh-speedmachiningcenter.Themachine,sbasenstructionandindividualcomponents,suchasthedrivetrain,spindleandCNC,mustbecapableofhandling(hedemandsofhardmilling.Thebaseconstructionmustbeextremelyrigidandhaveahighdegreeofdampingabilities.Thesecharacteristicsarefoundinmachinetoolswithbasesconstructedfrompolymerconcrete.Thesemachinestypicallyhavesixto10timesthedampingcharacteristicsofmachineswithcastironbases.Additionally,polymerncretehasexcellentmechanicalandthermalcharacteristics.Themachinetool,sdrivetrainshouldinrporatedigitaldrivetechnologyforoptim