先进制造技术----中英文翻译.docx

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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,whilewhitelayerincreaseswithincreasingIOOIwear.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,polymern

17、cretehasexcellentmechanicalandthermalcharacteristics.Themachinetool,sdrivetrainshouldinrporatedigitaldrivetechnologyforoptimalaccelerationanddeceleration.ThistechnologyallowstheCNCtoperfbnahighdegreeofcontouringaccuracyandgivesitexcellentdynamicscapabilities.Oneofthemostoverlookedcomponentsisthespin

18、dle.Thespindlemustbeabletoprovideagreatdealofflexibility,offeringhightorqueatlowSPindkspeedsandmaximumpowerforalargerangeofspindlespeeds.Anidealspindlesspeedrangesfrom100rpmto20,000rpmorhigher,dependingontheapplication.Hybridceramicbearingsintheconstructionofthespindleincreasespindlestiffness,accura

19、cyandtemperaturestability.Figure3.14showsa5-axismillingmachinedesignedforhardmilling,whichhasasimilarrequirementsashigh-speedmachining.Hgure3.14Mikron,sHSM5-axismachine.thepefL77ModemManufacturingTechnologyOneofthemaincontributorstosuccessfulhardmillingisthecuttingtool.Fbrroughinghardenedmaterials,e

20、ndmillswithfourormoreflutesarcrecommended.Theseprovidesmallchiploadswhilehavingthecapabilitytocutathigherfeedrates.Thecuttingtoolsshouldbeshortwithshortflutelengthsandhaveahelixangleofapproximately30o.A30ohelixhasproventobeoptimalforchipflowanddispersalofheat.Thecarbidesubstrateshouldalsobeconsidere

21、d.Onlycarbidetoolswithfineorultra-finegrainsizes,about0.5to0.6m,shouldbeused.Thesetoolsprovideincreasededgestrengthandreducebuilt-upedge.FormiJlinglargerhardenedcavitiesandcores,cuttingtlswithinsertsshouldbeconsidered.Carbideinsertsarelessexpensivethansolidcabideend-mills,andbyindexingtheinsert,tool

22、lifecanbeextended.However,thesetlsaretypicallynotdesignedforhighspindlespeeds.Thereisalsoasignificantsafetyriskifimproperlyhandled.Hardmillingputsagreatamountofstressonthecuttingtoolfromhighheatandabrasivewear.Tohelpovercomethesestresses,coatedcuttingtlsmustbeused.Coatingsofferaprotectivelayeronthet

23、ool,substantiallyincreasingtoollife.Coatingselectionshouldbemadebasedonindividualproperties.Titanium-basedcoatings,suchasTiCNandTiAlN,arethemostcommonforhardmilling.Thewearresistance,oritshardness,isthemostimportantpropertyofTiCN,whileTiAlNresistsheatandoxidationbetter.Thetlmakermayfurtherenhanceits

24、coatingsbyofferinguniquemultilayerblends.Floodolantisnotcommonlyusedinhadmilling.Hardmillingoftengeneratestremendousamountofheat,whichistransferredintothechipsandcausestheolanttovaporizeasithitsthehotchips.Theuseofolantcanalsocreatethenalinstabilitywiththecuttingtoo).Compressedairisusedtohelpdisplac

25、echipsduringcutting.Additionally,aCOmbinatiOnofoilandmistisoftenselected.Oilhelpsreducefriction,therebyincreasingtllifeandimprovingsurfacefinish.Whenusingoilandmist,anextractionunitshouldbeintegratedintothemachinetltohelpremovetheoilfromtheair.2. CAD/CAMAnalysisTheCAD/CAMsystemisanotherimportantcomp

26、onent.CAD/CAMsystemshavegreatlyadvancedovertheyears,andnowprovideavarietyofadvancedfeaturesandcapabilities.However,notallsystemsarecreatedequalandtherearestillmanythatdonothavethecapabilitiestocreatetipathsforhardmilling.AlthoughnoCAD/CAMsystemisdesignedexclusivelyforhardmilling,manyofthesystemsthat

27、offerHSMingcapabilitieshavethesamestrategiesforhardmillingbecausethetwoarerelated.Whenhardmilling,strategiesthatkeepthecuttingtoolinmotionshouldbeused.Thisensuresthetliscontinuouslycuttingwithanstantchipload,whichisoneofthemoredesirableconditionstomaintainwhenhardmilling.Beforetoolpathscanbeapplied,

28、acompleteanalysisoftepartmustbeperformed.Notallpartsaresuitableforhardmilling.Thespecificareastobemachinedshouldbeclearlyidentified,determining(hesmallestinternalradiusandlargestworkingdepth.Atlwitha4：1length-to-diameterratiocommonlydoesnotposeanyproblems.Problemsarisewhentheratiogrows.Whenratiosarc

29、excessive,hardnullingexperienceplaysanimportantroleindetermininghowsuccessfuloneis.HardmillingwithsmalldiametercuttingtoolsarepossibleaslongascareistakentomaintainanstantchiploadandmachineatminimaJDOCs.IfaCAD/CAMsystemdoesno(havethetoolstoverifyorsimulatetheNCcodedirectly,therearenumeroussoftwarepac

30、kagesonthemarketthatcan.Finally,properknow-howisvitaltosuccessfulhardmilling.AUofthenecessarycoonentsareofnousewithoutknowledgeoftheprocessingprocedures.Successfulhardmillingisbasedonspecificknow-how,advancedknowledgeHSMingtproperchoiceofcuttingt!sandclampingsystems,andusingaHSM-capableCAD/CAMsystem

31、.Aclearunderstandingofallthecomponentsprovidesbetterawarenessofwhatisneededtobesuccessfulathardmilling.3. PrecisionMachiningPrecisionmachiningisanyprocessusingacuttingtool,whetherturning,milling,orgrinding,whichformsaprecisedimension,form,andfinishofsurface.Theaccuracyheldmustbe10morless.Anyoperatio

32、nresultinginlessaccuracyisgenerallyconsideredconventionalmachining.Comparedtostandardmachiningoftraditionalmaterials(steel,Al),successfulprecisionmachiningofhardmaterialsismoresensitivetoparameterssuchasmachinetoolaccuracy,stiffness,tlholdcrdesign,cuttingtlmaterialandgeometry,Hxturing,clantpresentat

33、ion,andmachiningtechnique.Thepropertiesthatmakehardmaterialsattractiveforcommercialusealsomakethemextremelydifficulttomachinetothetolerancesrequiredbyadvancedapplications.Obtainingtightertolerancesonhardmaterialsisachallengethatmustbemetifmanufacturersaretoachievetheimprovedperformance;itsalsowheret

34、hefutureofmanufacturinglies.Amajorfactorthatinfluencestheproductionofclose-tolerancepartsfromhardmaterialsisthemachinetlitselfanditsparameters,includinginherentrepeatability,accuracy,stiffness,andtlesmoothnessoruniformityoftravel,spindlespeed,thermalstability,machineprotection,controlcapabilities,et

35、c.Virtuallyanymachinetlcanproducesomeclose-tolerancepartsifthefeedrateisreducedand(hecuttingtlchangedfrequently.Tosuccessfullyproduceprecisioncomponentstomeetmarketdemands,however,themachiningoperationmustbecost-effective,aswellasaccurateandrepeatable.AkeydesignfactorinmachinetlsistherigidityorStifi

36、heSSofthecuttingtooltotheworkpiece.Obviously,componentsandsubassembliesmustalsohavehighstiffness.Machinestiffnessisamajorcontributingfactortooverallmachineaccuracyandperformance.Stiffnessismeasuredbythedeflectionofanelementofthemachinewhenit,ssubjectedtoaload.Machineaccuracyisanothercriticaldesignpa

37、rameter.Tohavethecondencetocuthigh-precisionpartsonaproductionbasis,ifsnecessarythattheuserknowthe3-Daccuracyofthemachinetool.Thesamecriteriaapplytotlholders.Theytoomustprovideprecisionrigidity,andrepeatabilitytoproduceclose-toleranceparts,andtodosotheymustbekinematicallycorrect.Cuttingtoolsareanoth

38、erelementthatproduceamajoreffectontheproductionofprecisionpartsfromhardmaterials.Parameterstobeconsideredare：material,design,fabrication,tolerance,cost,andavailability.Tllifeisanenomicissuethatmustbeconsideredwhenmachiningprecisionpartsfromhardmaterials.WhileitmayperfbnWeH,atoolthatyoumustchangeafte

39、reveryIOOmmofcutlengthisnotaneconomicalsolutiontomachiningthesematerials.Tllifedependsuponthematerialtobemachinedandtheprocess.Workholdingisanotherkeyclement.Materialconsiderationsareimportant.先进制造技术尽管裁断的深度是由材料去除率的总额决定的，增加径向的裁断深度同样能够增加磨损率。就像增加进给速度一样，工具的使用寿命会随着切削深度的加深而缩短。因此，工具的使用寿命与磨损率能够像预期那样保持平衡。每个金

40、属在切削过程中会产生三个力：切向力，即零件运转时产生的力;径向力，由工件材料切削深度的阻隔产生的力；纵向力，利用进给速度产生的力。这些力比机器运转过程中产生的力强30%至I80%o例如，在洛氏硬度62HRC的强度下，分别经过预热处理和热处理,纵向力会从30%增加到50%,切向力会从30%增加到50%,径向力会从70%增加到100%。因此,机床必须能够承受不断增加的切削力，尤其是径向的切削力。切削液能够影响白层的产生，因为白层是物象变化在表面发生的结果，当冷却工件表面时，切削液能够减轻热损坏。一些报道认为切削液会消除白层，但却有研究表明切削液没有这样的作用。刀具状态也是一个很重要的因素，然而白层

41、的增加同样伴随着刀具的磨损。如果硬态切削能够代替精磨操作，硬态切削的产品表面光洁度能够与精磨操作相媲美。与精磨操作不同的是，表面光洁度是由大小，形状，强度和在磨削砂轮中磨粒的作用决定的。硬车削表面通常是由切削过程中形成的几何图形决定的，其中主要是由切削工具的进给和刀尖半径决定的。对于磨削圆柱的应用，其砂轮和工件必须能够顺利的旋转。其次，砂轮飞快旋转的同时工件要缓慢的旋转。如果旋转的构件不完全同心，组合的缺陷和旋转速度的细微差别会引起圆柱的凸角。当生产的几何图形不够圆时，这会影响最终的生产。另一方面，对于硬切削来说，工件或者切削工具不能同时旋转。因此，机器加工表面将会与机床主轴和紧挨机床的中心线

42、的机床纵向的方向一样精准。摩擦的另一个缺点是，在磨轮和工作部件的接触点，在表面会产生许多热能，甚至当合理应用冷却液体时，工作表面应力升高和热检查会导致地上部分的工作部件在运行中过早失效。使用硬态切削会产生较少的热量，而且如果合理使用，伴随着脆性材料的去除，产生的热量将被带走。因此，在缺乏应力升高和热检查的条件下，成品依然能够生产。HPM的另一个优点是,工作部件能够承受洛氏硬度65HRC的强度，在工作部件使用市售陶瓷插件的条件下，普通车床依然能够使用。两个方面可以能够节约，分别是工艺设计和资本投资。在工艺设计方面，耗时的加工，安装程序以及工具的应用明显的减少了。另一方面,砂轮的改变是旷日持久的，

43、防护装置必须拆下，连同主轴锁紧螺母。旧磨轮必须更换，而且新轮平衡会焕目一新。换轮可能会花费换瓷片插件一百倍的时间，换瓷片插件仅仅需要简单的索引或在架更换即可。设备也不贵，一个车床明显比一个做类似工作的生产磨床花费的少，就像之前己经提过的，安装程序更加容易，更加快捷，车床在构造方面也更加容易，这没有往复滑动造成的磨损，维修或更换一一因为维护更加容易。3.7.2硬铳削在过去的几年中，一个深入人心的加工方面的进步是硬铳削，通常模具制造商使用硬铳切P20,H13和其他工具钢。这些材料的硬度范围是从45到64HRC,而且他们是传统的放电加工，但是新技术使硬铳削成为一个可行的替代方案，成功的硬铳削需要几个

44、组件组合在一起机床，工具柄，切割工具，计算机辅助设计和加工“专有技能”。1 .机械因素机床是最重要的组成部分。机床最基本的要求是必须为硬铳而设计，并且还要拥有与高速加工中心相同的特征。机床的基本结构和单个组件，例如驱动系统，主轴和CNC,必须能够承受硬切削的强度。机床的基本结构要求非常严格，并且要能够增强阻尼，在聚合物混凝土建造的机床中能够发现这些特征。不仅如此，聚合物混凝土还具有力学和热特性。机床的驱动系统应该包含能够优化加减速度的数字驱动技术，这项技术能够使CNC达到较高的成形精度，并赋予它高超的动态能力。图3.14Mikron的五轴铳床主轴是最容易被忽视的一个重要组件之一，主轴必须能够提

45、供较好的灵活性，在较低的主轴转速的情况下提供较大的扭转力，在一定的主轴转速的范围内使功率最大化。一个合理的主轴转速的范围是从IoORPM到20000RPM范围内或者更高，这取决于主轴的应用程度。在主轴结构中的混合陶瓷轴承能够增加主轴的刚度，精确度和温度稳定性。图3.14的数据表明一个五轴铳床是专为硬切削设计的，这与高速加工有着相似的要求。切削工具是硬铳削成功工作的一个主要因素。对于粗加工的硬化材料，有至少四个凹槽的端铳刀值得推荐。当以较高的进给速度切削时，它们能够提供负载芯片。刀具的槽长应该较短，还应该有一个接近30度的螺旋角。经验证，一个30度的螺旋角有利于切屑瘤的产生和切削热的扩散。除此之

46、外，还应该考虑到硬质合金基体。只能使用超细晶体尺寸的硬质合金，大约05微米到0.6微米。这些工具能够增加边缘的强度并且减少积屑瘤。当铳削硬化的模槽时，应该考虑到有嵌入物的刀具。硬质合金刀片比固体硬质合金端铳刀要便宜，而且插入刀片后，会延长刀具的使用寿命。然而，这些刀具并不是为高转速主轴而设计的，如果操作不当，也会有重大的安全风险。硬铳削从高温到磨粒磨损都给切削工具施加了很大的压力，为了承受这些压力，必须要使用涂层刀具。涂层给刀具增加了一个保护层，这样能够增加工具的使用寿命。涂层的选择应该以其独有的属性为基础。钛基涂层，例如TiCN和TiALN,对于硬铳削来说是很常见的。耐磨性和高硬度是TiCN

47、最重要的特性，TiALN的耐热性和抗氧化性更强些。工具制造商可以通过提供特制的多层共混物来进一步增加涂层。在硬铳削中不会经常使用冷却液体。硬铳削会产生大量热能，但是当冷却液接触到表面时会蒸发。使用涂层同样能够导致刀具的热不稳定性。在切削过程中压缩空气能够代替芯片，除此之外，油雾组合的产品同样是精选出来的。润滑油能够减少摩擦，因此润滑油能够增加工具的使用寿命和表面抛光度。2 .CAD/CAM的分析CAD/CAM系统是另一个重要的组成部分，该系统在近年来取得了显著的进步，现在更是增加了一系列先进的特性和功能。然而并不是所有的系统都能够与之比拟，这些系统不能为硬铳削创建刀具轨迹。尽管CAD/CAM系

48、统不是专门为硬铳削设计的，但是对于硬铳削来说，许多拥有高速加工能力的系统有同样的功能，因为这两者之间是有一定联系的。这确保了工具持续的用一个一成不变的切削力进行切割，这是维持理想状态的条件之一。在刀具轨迹应用之前，这部分的完整分析必须完成，不是所有的部分都适用于硬铳削，加工的特定领域应该清楚的标明，这决定了最小的内半径和最长的工作深度。通常来说，一个4:1的长径比的工具不会造成任何问题。当长径比增大时，问题就会出现，当长径比过大时，硬磨的经验在决定它有多成功方面发挥了关键作用。而采用小直径刀具的硬铳削是可行的，只要小心地保持恒定的切屑负荷和机器以最低的DOCS运行。如果CAD/CAM系统没有直

49、接验证或者模拟数控代码的工具，市场上有很多可以进行这类操作的软件包可以采用。最后，适当的诀窍对于成功的硬铳削是至关重要的。如果不懂处理程序的知识，那么所有的必须部分都是没有用的。成功的硬铳削的依据有专业技巧，先进的高速切削HSM知识，切割工具的合理选择，合模装置以及使用CAD/CAM系统加工能力。对所有的组件有一个清晰的了解，这能使工作人员认识到，对于成功的硬铳削，什么是必需的。3 .精密加工精密加工是使用切削工具的过程，无论是车削，硬铳削，磨削，这会形成一个精密的尺寸，形状和表面光洁度。精密加工必须保证在10微米以下。任何导致不准确的操作通常被称为传统的机械加工。相比于传统材料的标准加工，成功的精密硬质材料加工对参数更加敏感。例如：机床精度，刚度