模具專業(yè)英語完整版電子課件

模具專業(yè)英語目錄Chapter1IntroductionofMold（模具概論）Chapter2IntroductionofMoldMaterial（模具材料簡介）Chapter3PressProcessandDieDesign（冷沖壓工藝及模具）Chapter4PlasticsFormingandMoldDesign（塑料成型工藝及模具）目錄Chapter5ForgingProcessesandDieDesign（鍛造工藝及模具）Chapter6BasicandSpecialMachining（普通機械加工與特種加工）Chapter7TheApplicationofComputerinDesignandManufactureofMoldandDie（計算機在模具設(shè)計與制造中的應(yīng)用）Chapter8QuotationandContractforMoldandDie（模具的報價與合同）Chapter1IntroductionofMold（模具概論）Lesson1TheDefinitionandFunctionofMoldLesson2TheClassificationofMoldLesson1TheDefinitionandFunctionofMoldInmodernindustrialproduction,moldisanimportanttechnicalequipmentusedinshapingprocessofmaterial(includingmetalmaterialandnonmetalmaterial).Meanwhile,itisthe“magnifyingglassofefficiencyandprofit”totherawmaterialandequipment,becausethevalueofthefinalproductondieisoftentensof,evenhundredsoftimesasvaluableasthatofthedieitself.Dieindustryisthebasicindustryofnationaleconomy,anditiscalled“themotherofindustry".Everyaspectofhumanlifesuchasclothes,food,housingandtransportationisNEXTBACKLesson1TheDefinitionandFunctionofMoldcloselyconnectedwithdieindustry.Therefore,thelevelofdietechnologyhasbeenasignificantsymboltomeasureacountry'sdevelopinglevelofmechanicalindustry.Notes:1.becausethevalueofthefinalproductondieisoftentensofevenhundredsoftimesasvaluableasthatofthedieitself.譯文:因為模具生產(chǎn)出的最終產(chǎn)品的價值,往往是模具自身價值的數(shù)十倍,乃至上百倍。解析:tensof,evenhundredsoftimes:數(shù)十倍,乃至上百倍。as+adj.+as:和····一樣BACKPREVNEXT@機械知網(wǎng)Lesson1TheDefinitionandFunctionofMold2.Everyaspectofhumanlifesuchasclothing,food,housingandtransportationiscloselyconnectedwithdieindustry.譯文:人類的衣、食、住、行諸方面都離不開模具。解析:beconnectedwith:和……有聯(lián)系/關(guān)系。becloselyconnectedwith:和……有密切的聯(lián)系/關(guān)系。BACKPREVLesson2TheClassificationofMoldAccordingtothetypesofrawmaterial,moldcanbedividedintotwomainkinds:metalproductsandnonmetalproducts.BACKNEXTLesson2TheClassificationofMoldNotes:Accordingtothetypesofrawmaterial,moldcanbedividedintotwomainkinds:metalproductsandnonmetalproducts.譯文:根據(jù)制品所用的原材料種類,模具可分為金屬制品模具和非金屬制品模具兩大類。解析:accordingto:依據(jù),按照。bedividedinto……被分成……。BACKPREVChapter2IntroductionofMoldMaterialLesson3SteelsLesson4HeatTreatingofSteelLesson3SteelsSteels(firstmadeinChinaandJapanaround600-800AC)aregenerallydividedintothecategoriesofcarbonsteelsandalloysteels(includingtoolsteels).CarbonSteelsCarbonsteelsareusedextensivelyintoolconstruction.Carbonsteelsarethosesteelswhichonlycontainironandcarbon,andsmallamountsofotheralloyingelements.Carbonsteelsarethemostcommonandleastexpensivetypeofsteelsusedfortools.Thethreeprincipaltypesofcarbonsteelsusedfortoolingarelowcarbon,mediumcarbon,andhighcarbonsteels.LowBACKNEXTLesson3Steelscarbonsteelcontainsbetween0.05%and0.3%carbon.Mediumcarbonsteelcontainsbetween0.3%and0.7%carbon.Andhighcarbonsteelcontainsbetween0.7%and1.5%carbon.Asthecarboncontentisincreasedincarbonsteel,thestrength,toughness,andhardnessalsoincreasewhenthemetalisheattreated.Lowcarbonsteelsaresoft,toughsteelsthatareeasilymachinedandwelded.Duetotheirlowcarboncontent,thesesteelscannotbehardenedexceptbycasehardening.Lowcarbonsteelsarewellsuitedforthefollowingapplications:toolbodies,handles,dieshoes,andBACKPREVNEXTLesson3Steelssimilarsituationswherestrengthandwearresistancearenotrequired.Mediumcarbonsteelsareusedwheregreaterstrengthandtoughnessarerequired.Sincemediumcarbonsteelshaveahighercarboncontenttheycanbeheattreatedtomakepartssuchasstuds,pins,axles,andnuts.Steelsinthisgrouparemoreexpensiveaswellasmoredifficulttomachineandweldthanlowcarbonsteels.Highcarbonsteelsarethemosthardenabletypeofcarbonsteelandareusedfrequentlyforpartswherewearresistanceisanimportantfactor.OtherapplicationswhereBACKPREVNEXTLesson3Steelshighcarbonsteelsarewellsuitedincludedrillbushings,locators,andwearpads.Sincethecarboncontentofthesesteelsissohigh,partsmadefromhighcarbonsteelarenormallydifficulttomachineandweld.AlloySteelsAlloysteelsarebasicallycarbonsteelswithadditionalelementsaddedtoalterthecharacteristicsandbringaboutapredictablechangeinthemechanicalpropertiesofthealloyedmetal.Alloysteelsarenotnormallyusedformosttoolsduetotheirincreasedcost,butsomehavefoundfavorforBACKPREVNEXTLesson3Steelsspecialapplications.Thealloyingelementsusedmostofteninsteelsaremanganese,nickel,molybdenum,andchromium.Anothertypeofalloysteelfrequentlyusedfortoolingapplicationsisstainlesssteel.Stainlessteelisatermusedtodescribehighchromiumandnickel-chromiumsteels.Thesesteelsareusedfortoolswhichmustresisthightemperaturesandcorrosiveatmospheres.Somehighchromiumsteelscanbehardenedbyheattreatmentandareusedwhereresistancetowear,abrasion,andcorrosionarerequired.TypicalapplicationswhereahardenableBACKPREVNEXTLesson3Steelsstainlesssteelissometimespreferredareplasticinjectionmolds:Herethehighchromiumcontentallowsthesteeltobehighlypolishedandpreventsdeteriorationofthecavityfromheatandcorrosion.notes:1.Carbonsteelsarethosesteelswhichonlycontainironandcarbon,andsmallamountsotheralloyingelements.Carbonsteelsarethemostcommonandleastexpensivetypeofsteelusedfortools.BACKPREVNEXTLesson3Steels譯文:碳鋼是指那些僅僅由鐵和碳以及少量的其他合金元素構(gòu)成的鋼。碳鋼是一種最常見的、最廉價的制造工具的鋼。解析:此句中which是關(guān)系代詞,引導定語從句,修飾前面的名詞steels,并充當定語從句的主語。usedfortools是過去分詞短語作后置定語,修飾中心詞steels,它也可等同于定語從句which/that。

2.Lowcarbonsteelsarewellsuitedforthefollowingapplications:toolbodies,handles,dieshoes,andsimilarsituationswherestrengthandwearresistancearenotrequired.BACKPREVNEXTLesson3Steels譯文:低碳鋼很適合于以下用途:工具主體、把柄、模腳以及一些不要求強度和耐磨性的類似情況。解析:此句中where是關(guān)系副詞,引導定語從句,修飾前面的名詞similarsituations。3.Sincemediumcarbonsteelshaveahighercarboncontenttheycanbeheattreatedtomakepartssuchasstuds,pins,axles,andnuts.譯文:由于中碳鋼含碳量較高,所以經(jīng)過熱處理后可被制成如圓柱頭螺栓、銷、軸和螺母之類的部件。解析:此句中since是從屬連詞,引導原因狀語從句,譯為“由于”。句中studs,pins,axles,andnuts譯為“圓柱頭螺栓、銷、軸和螺母”。BACKPREVNEXTLesson3Steels4.Highcarbonsteelsarethemosthardenabletypeofcarbonsteelandareusedfrequentlyforpartswherewearresistanceisanimportantfactor.譯文:高碳鋼是一種最可硬化的碳鋼,常用于對耐磨性要求非常高的部件。解析:此句中where是關(guān)系副詞,引導定語從句。5.Thealloyingelementsusedmostofteninsteelsaremanganese,nickel,molybdenum,andchromium.譯文:鋼中最常用的合金化元素是錳、鎳、鑰和鉻。解析:此句中element譯為“元素”。它還有“適合的環(huán)境”之意。例如:BACKPREVNEXTLesson3SteelsYou'reinyourelementoncetheconversationturnstomovies.談起電影,你便如魚得水。6.Thesesteelsareusedfortoolswhichmustresisthightemperaturesandcorrosiveatmospheres.譯文:這些鋼用于必須耐高溫和耐腐蝕性環(huán)境的工具。解析:此句中resist譯為“耐……”,resistdoing譯為“防……”。7.Somehighchromiumsteelscanbehardenedbyheattreatmentandareusedwhereresistancetowear,abrasion,andcorrosionarerequired.譯文:一些高鉻鋼能夠被熱處理硬化,用于有耐磨損、耐BACKPREVNEXTLesson3Steels大氣腐蝕要求的場合解析:此句中where是關(guān)系副詞,引導狀語從句。8.Typicalapplicationswhereahardenablestainlesssteelissometimespreferredareplasticinjectionmolds:Herethehighchromiumcontentallowsthesteeltobehighlypolishedandpreventsdeteriorationofthecavityfromheatandcorrosion.譯文:常選用可硬化不銹鋼的典型場合是塑料注射模具:因為高含鉻量使得鋼材具有很好的拋光性,而且能夠防止型腔由于受熱和腐蝕而產(chǎn)生性能的退化。解析:此句中prevent...from譯為“阻止,妨礙”。BACKPREVLesson4HeatTreatingofSteelSpecificationsforheat-treatingprocessesareamongthemostimportantofthoseshownonanengineeringdrawing.Properheattreatmentisapowerfultoolfordevelopingthebestpossiblepropertiesthatamaterialcanpossess.Ingeneral,heattreatmentmaybedescribedasacombinationofheatingandcoolingoperations,timedandappliedtoametaloranalloyinthesolidstateinawaythatwillproducedesiredproperties.Principally,heattreatmentisusedtoproducestrengthening,butsomeheat-treatingprocessessoften,toughen,orotherwiseenhanceproperties.BACKNEXTLesson4HeatTreatingofSteelInternally,ametaloranalloyconsistsofoneormorekindsofatomspackedtogetherinorderlythree-dimensionalarrangementscalledcrystals.Thecrystals,inturn,arebondedtogetherindiversewayswhicharedescribedintermsofmicrostructureorgrainstructure.Anygivenstructurecanbealteredtosomeextentbyplasticdeformationfromcompressive,tensile,orshearforces,buttheavailabletime-temperaturetreatmentsprovideagreatervarietyofproperties.Heattreatmentsarecarefullycontrolledcombinationsofsuchvariablesastime,temperature,rateoftemperaturechange,andfurnaceBACKPREVNEXT@機械知網(wǎng)Lesson4HeatTreatingofSteelatmosphere.Theselectionofaspecifictreatmentmustbebaseduponknowledgeofthepropertiesdesiredinthefinishedpart.Thereisavailabletodayamultitudeofmetalsandalloysdesignedforvariouspurposes.Therearealsomanydifferentheat-treatingprocesses.Notallthetreatmentscanbeusedwitheachmetaloralloy.Inotherwords,thetreatmentselectedmustbeonethatiscompatiblewiththespecifiedmaterial.Heattreatmentcannotbeselectedindependentlyofmaterial.Oneisjustasimportantastheother.BACKPREVNEXTLesson4HeatTreatingofSteelReasonsforHeatTreatingFerrousMetals.Ferrouspartsareheat-treatedforseveralreasons:torelieveinternalstresses,tochangethemicrostructurebyrefiningthegrainsizeorproducinguniformgrainthroughoutapart,toalterthesurfacechemistrybyaddingordeletingelements,andtostrengthenametalpart.TreatmentofFerrousMaterials.Ironisthemajorconstituentinthesteelsusedintooling,towhichcarbonisaddedinorderthatthesteelmayharden.AlloysareputintosteeltoenableittodeveloppropertiesnotpossessedBACKPREVNEXTLesson4HeatTreatingofSteelbyplaincarbonsteel,suchastheabilitytohardeninoilorair,increasedwearresistance,highertoughness,andgreatersafetyinhardening.Heattreatmentofferrousmaterialsinvolvesseveralimportantoperationswhicharecustomarilyreferredtoundervariousheadings,suchasnormalizing,spheroidizing,stressrelieving,annealing,hardening,tempering,andcasehardening.Normalizinginvolvesheatingthematerialtoatemperatureofabout100℉-200℉(55℃-100℃)abovetheBACKPREVNEXTLesson4HeatTreatingofSteelcriticalrangeandcoolinginstillair.Thisisabout100℉(55℃)overtheregularhardeningtemperature.Thepurposeofnormalizingisusuallytorefinegrainstructuresthathavebeencoarsenedinforging.Withmostofthemedium-carbonforgingsteels,alloyedandunalloyed,normalizingishighlyrecommendedafterforgingandbeforemachiningtoproducemorehomogeneousstructures,andinmostcases,improvedmachinability.High-alloyair-hardenedsteelsarenevernormalized,sincetodosowouldcausethemtohardenanddefeattheBACKPREVNEXTLesson4HeatTreatingofSteelprimarypurpose.Spheroidizingisaformofannealingwhich,intheprocessofheatingandcoolingsteel,producesaroundedorglobularformofcarbide-thehardconstituentinsteel.Toolsteelsarenormallyspheroidizedtoimprovemachinability.Thisisaccomplishedbyheatingtoatemperatureto1380℉-1400℉(749℃-760℃)forcarbonsteelsandhigherformanyalloytoolsteels,holdingatheatonetofourhours,andcoolingslowlyinthefurnace.StressRelieving.Thisisamethodofrelievingtheinternalstressessetupinsteelduringforming,coldworking,andBACKPREVNEXTLesson4HeatTreatingofSteelcoolingafterweldingormachining,itisthesimplestheattreatmentandisaccomplishedmerelybyheatingto1200℉-1350℉(649℃-732℃)followedbyairorfurnacecooling.Largediesareusuallyroughedout,thenstress-relievedandfinish-machined.Thiswillminimizechangeofshapenotonlyduringmachiningbutduringsubsequentheattreatingaswell.Weldedsectionswillalsohavelocked-instressesowingtoacombinationofdifferentialheatingandcoolingcyclesaswellastochangesincrosssection.Suchstresseswillcauseconsiderablemovementinmachiningoperations.BACKPREVNEXTLesson4HeatTreatingofSteelAnnealing.Theprocessofannealingconsistsofheatingthesteeltoanelevatedtemperatureforadefiniteperiodoftimeand,usually,coolingitslowly.Annealingisdonetoproducehomogenizationandtoestablishnormalequilibriumconditions,withcorrespondingcharacteristicproperties.Toolsteelisgenerallypurchasedintheannealedcondition.Sometimesitisnecessarytoreworkatoolthathasbeenhardened,andthetoolmustthenbeannealed.Forthistypeofanneal,thesteelisheatedslightlyaboveitscriticalrangeandthencooledveryslowly.BACKPREVNEXTLesson4HeatTreatingofSteelHardening.Thisistheprocessofheatingtoatemperatureabovethecriticalrange,andcoolingrapidlyenoughthroughthecriticalrangetoappreciablyhardenthesteel.Tempering.Thisistheprocessofheatingquenchedandhardenedsteelsandalloystosometemperaturebelowthelowercriticaltemperaturetoreduceinternalstressessetupinhardening.CaseHardening.TheadditionofCarbontothesurfaceofsteelpartsandthesubsequenthardeningoperationsareimportantphasesinheattreating.Theprocessmayinvolvetheuseofmoltensodiumcyanidemixtures,packBACKPREVNEXTLesson4HeatTreatingofSteelcarburizingwithactivatedsolidmaterialsuchascharcoalorcoke,gasoroilcarburizing,anddrycyaniding.Notes:1.Ingeneral,heattreatmentmaybedescribedasacombinationofheatingandcoolingoperations,timedandappliedtoametaloranalloyinthesolidstateinawaythatwillproducedesiredproperties.譯文:通常,熱處理被描述為對金屬或合金按-定的速度進行加熱和冷卻的一種處理過程,以此來獲得理想的性能。解析:describeas:描述為applyto:將……應(yīng)用于……inaway譯為“在某種程度上,稍稍”。又如:IlikethenewBACKPREVNEXTLesson4HeatTreatingofSteelstyles,inaway.在某種程度上我喜歡這些新款式。2.Anygivenstructurecanbealteredtosomeextentbyplasticdeformationfromcompressive,tensile,orshearforces,buttheavailabletime-temperaturetreatmentsprovideagreatervarietyofproperties.譯文:由壓縮、拉伸或剪切等作用力帶來的塑性變形不但可以在某種程度上改變?nèi)魏谓o定的物質(zhì)結(jié)構(gòu),而且還能結(jié)合給定的熱處理工藝獲得較寬范圍內(nèi)的性能的變化。解析:句中g(shù)iven譯為“特定的,給定的”。又如:Wewillmeetatagiventimeandlocation.我們將在指定的時間和地點見面。BACKPREVNEXTLesson4HeatTreatingofSteel3.Theselectionofaspecifictreatmentmustbebaseduponknowledgeofthepropertiesdesiredinthefinishedpart.譯文:具體熱處理工藝的選擇必須以成品零件所期望的性能為基礎(chǔ)。解析:此句中basedupon譯為“以……為基礎(chǔ)”。又如:Yourconclusionshouldbebaseduponcarefulresearch.你應(yīng)該以審慎的研究為基礎(chǔ)而下結(jié)論4.Notallthetreatmentscanbeusedwitheachmetaloralloy.Inotherwords,thetreatmentselectedmustbeonethatiscompatiblewiththespecifiedmaterial.BACKPREVNEXTLesson4HeatTreatingofSteel譯文:并非所有的熱處理都能用于每種金屬或合金。換句話說,選擇的熱處理工藝必須和指定材料所需要的熱處理工藝相一致。解析:句中notall表部分否定,有時相當于all...not...。又如:Allisnotgoldthatglitters.發(fā)光的并不總是金子。5.Heattreatmentofferrousmaterialsinvolvesseveralimportantoperationswhicharecustomarilyreferredtoundervariousheadings,suchasnormalizing,spheroidizing,stressrelieving,annealing,hardening,tempering,andcasehardening.BACKPREVNEXTLesson4HeatTreatingofSteel譯文:含鐵材料的熱處理包含幾個重要操作,常常被貫以如下稱謂,例如正火、球化、應(yīng)力消除、退火、淬火、回火和表面硬化。解析:句中suchas譯為“例如……”,“像這種的”。referto:提到,談到,指的是。6.Thepurposeofnormalizingisusuallytorefinegrainstructuresthathavebeencoarsenedinforging.譯文:正火的日的通常是為了細化鍛造過程中被粗化的晶粒。解析:句中g(shù)rainstructures譯為“晶粒”。that在句中是關(guān)系代詞,引導定語從句,修飾先行詞grainstructures,并代替先行詞在從句中作主語。BACKPREVNEXTLesson4HeatTreatingofSteel7.Largediesareusuallyroughedout,thenstress-relievedandfinish-machined.譯文:大型模具通常首先制坯,然后消除應(yīng)力和精加工。解析:此句中die譯為“模具”(名詞)。8.Weldedsectionswillalsohavelocked-instressesowingtoacombinationofdifferentialheatingandcoolingcyclesaswellastochangesincrosssection.譯文:不同加熱和冷卻循環(huán)的組合以及橫截面的改變,使得焊接區(qū)域也存在牢固的應(yīng)力。解析:句中l(wèi)ocked-in是形容詞,譯為“牢固的”。oweto:歸功于,由于。aswellas譯為“也,又”。crosssection譯為“橫截面”。BACKPREVNEXT@機械知網(wǎng)Lesson4HeatTreatingofSteel9.Sometimesitisnecessarytoreworkatoolthathasbeenhardened,andthetoolmustthenbeannealed.譯文:有時有必要再次加工已經(jīng)硬化的工件,那么這個工件必須退火。解析:此句中that是關(guān)系代詞,引導定語從句,修飾先行詞tool,并代替先行詞在從句中作主語。句中itisnecessaryto譯為“有必要……”。又如:Isitnecessaryforyoutobuysomanydressesatatime?你有必要一次買那么多衣服嗎?10.Theprocessofannealingconsistsofheatingthesteeltoanelevatedtemperatureforadefiniteperiodoftimeand,usually,coolingitslowly.AnnealingisdonetoproduceBACKPREVNEXTLesson4HeatTreatingofSteelhomogenizationandtoestablishnormalequilibriumconditions,withcorrespondingcharacteristicproperties.譯文:退火過程常為加熱鋼至高溫并保持-定的時間,然后慢慢冷卻。退火是為了達到均-化并且建立正常的平衡條件,以獲取相應(yīng)的性能。解析:句中consistof譯為“由……組成”。11.Theprocessmayinvolvetheuseofmoltensodiumcyanidemixtures,packcarburizingwithactivatedsolidmaterialsuchascharcoalorcoke,gasoroilcarburizing,anddrycyaniding.BACKPREVNEXTLesson4HeatTreatingofSteel譯文:這個過程包括使用熔融氰化鈉混合物,用活性固體材料例如木炭、焦炭或者用能夠提供碳原子的氣體、油類和干的氰化物填滿滲碳介質(zhì)。解析:此句中suchas譯為“例如”。BACKPREVChapter3PressProcessandDieDesign（冷沖壓工藝及模具）Lesson5FormingofSheetMetalsLesson6PressProcessandProductApplicationLesson7ClassificationofDiesLesson8PressesNEXTChapter3PressProcessandDieDesign（冷沖壓工藝及模具）Lesson9ShearOperationLesson10BendingOperationLesson11DrawingOperationLesson12CompoundandProgressiveDiesPREVLesson5FormingofSheetMetalsSheetmetalsaregenerallycharacterizedbyahighratioofsurfaceareatothickness.Formingofsheetmetalsiscarriedoutgenerallybytensileforcesintheplaneofthesheet;otherwisetheapplicationofcompressiveforcescouldleadtobuckling,folding,andwrinklingofthesheet.Inbulkdeformationprocessessuchasforging,rolling,extrusion,andwiredrawing,thereisanintentionalchangeinthethicknessorthelateraldimensionsoftheworkpiece.However,inmostsheet-formingprocessesanythicknesschangeisduetothestretchingofthesheetunderBACKNEXTLesson5FormingofSheetMetalstensilestresses(Poisson'sratio).Thicknessdecreasesshouldgenerallybeavoidedastheycouldleadtoneckingandfailure.MethodofSheetShearingTheshearingprocessinvolvescuttingsheetmetalbysubjectingittoshearstresses,usuallybetweenapunchandadiemuchlikeapaperpunch.Thepunchanddiemaybeanyshape;theymaybecircularorstraightbladessimilartoapairofscissors.Themajorvariablesintheshearingprocessare:thepunchforceP,thespeedofthepunch,lubrication,surfaceconditionandmaterialsoftheBACKPREVNEXTLesson5FormingofSheetMetalspunchanddie,theircornerradii,andtheclearancebetweenthepunchandthedie.Inadditiontotheshearingprocessesdescribedabove,thereareothertechniquesforcuttingsheetmetals.Thesheetorplatemaybecutwithasaw,suchasabandsaw.Thisisachipremovalprocess.Inanotherprocess,calledshaving,theextramaterialfromaroughshearededgeistrimmedbycutting(similartoremovingathinlayerofwoodwithachisel).Flamecuttingisanothercommonmethod,particularlyforthicksteelplates.Thisprocesshaswideapplicationsinbuildingshipsandheavystructuralcomponents.BACKPREVNEXTLesson5FormingofSheetMetalsInfrictionsawing,adiskorbladerubsagainstthesheetorplateatsurfacespeedsupto25000ft/min(130m/s)fordisks,and15000ft/min(80m/s)forblades.Inthisprocess,thefrictionalenergyisconvertedintoheat,whichthenrapidlysoftensanarrowzoneofthemetal.Thecontinuousmovementofthediskorbladethenpullsthesoftenedmetaloutofthecuttingzone.Tohelpremovethematerial,sometoolshaveteethornotches.Thefrictionsawingprocessismoresuitableforferrousalloys,asnonferrousmetalshaveatendencytoadheretothediskorbladeandinterferewiththecuttingoperation.BACKPREVNEXTLesson5FormingofSheetMetalsNotes:1.Sheetmetalsaregenerallycharacterizedbyahighratioofsurfaceareatothickness.譯文:金屬板料的-般特征是表面積和厚度之間的比率很高。解析:becharacterizedby:被賦予……的特征。aratioof……的比率2.Formingofsheetmetalsiscarriedoutgenerallybytensileforcesintheplaneofthesheet;otherwisetheapplicationofcompressiveforcescouldleadtobuckling,folding,andwrinklingofthesheet.BACKPREVNEXTLesson5FormingofSheetMetals譯文:板料通常通過在板料面上施加拉力來成形,而如果使用壓縮力就可能導致板料的彎曲、折疊和褶皺。解析:此句為一個用連接詞otherwise表轉(zhuǎn)折的復合句,其中前句的主語是現(xiàn)在分詞短語formingofsheetmetals。3.However,inmostsheet-formingprocessesanythicknesschangeisduetothestretchingofthesheetundertensilestresses(Poisson'sratio).譯文:然而,在大多數(shù)板料成形過程中,任何厚度的變化都是由于板料在拉應(yīng)力作用下的延伸(泊松比)。解析:bedueto:由于,應(yīng)歸于。BACKPREVNEXTLesson5FormingofSheetMetals4.Theshearingprocessinvolvescuttingsheetmetalbysubjectingittoshearstresses,usuallybetweenapunchandadiemuchlikeapaperpunch(Fig.5-1).譯文:沖裁過程是指在切應(yīng)力的作用下對板料進行切割,通常是在一個凸模和一個凹模之間,極似紙張打孔器的操作(圖5-1)。解析:involve:包括,涉及,牽連。subjectwtow:使某人或某物經(jīng)歷或遭受某事物。5.Inadditiontotheshearingprocessesdescribedabove,thereareothertechniquesforcuttingsheetmetals.譯文:除了上述沖裁過程外,還有其他的板料切割方法。解析:inadditionto:加之……,除……之外BACKPREVNEXTLesson5FormingofSheetMetals6.Inanotherprocess,calledshaving,theextramaterialfromaroughshearededgeistrimmedbycutting(similartoremovingathinlayerofwoodwithachisel).譯文:在另一個被稱為缺口修整加工的過程中,通過切割對粗糙的沖裁邊緣的多余材料進行切邊(此過程就像用鑿子鑿去木材上薄薄的一層)解析:calledshaving前其實省略了whichis,合起來是作為修飾中心詞anotherprocess的定語從句。7.Flamecuttingisanothercommonmethod,particularlyforthicksteelplates.Thisprocesshaswideapplicationsinbuildingshipsandheavystructuralcomponents.BACKPREVNEXTLesson5FormingofSheetMetals譯文:火焰切割是另一種常見的方法,尤其適用于切割厚鋼板。這種方法廣泛地應(yīng)用于造船和鍛造巨型結(jié)構(gòu)的零件。解析:haveapplicationin:應(yīng)用于某方面。8.Infrictionsawing,adiskorbladerubsagainstthesheetorplateatsurfacespeedsupto25000ft/min(130m/s)fordisks,and15000ft/min(80m/s)forblades.譯文:在摩擦割鋸中,鋸盤或鋸片摩擦表面板料或金屬板的速度達到了鋸盤為25000英尺/分鐘(130米/秒),鋸片為15000英尺/分鐘(80米/秒)。解析:rub摩擦。rub用于詞組中表示“與……相摩擦”,其后-定要接介詞againstspeed在此句中為動詞。句中upto意為“達到”。BACKPREVNEXTLesson5FormingofSheetMetals9.Inthisprocess,thefrictionalenergyisconvertedintoheat,whichthenrapidlysoftensanarrowzoneofthemetal.譯文:在此過程中,摩擦能轉(zhuǎn)換為熱能,然后熱能迅速軟化金屬板狹窄的部分。解析:which引導的是一個非限制性定語從句,修飾heatoconvert:轉(zhuǎn)變,轉(zhuǎn)換soften:使變軟,軟化。10.Thefrictionsawingprocessismoresuitableforferrousalloys,asnonferrousmetalshaveatendencytoadheretothediskorbladeandinterferewiththecuttingoperation.BACKPREVNEXTLesson5FormingofSheetMetals譯文:摩擦鋸割工藝更適合鋼鐵類合金,而有色金屬在鋸割時則有粘在鋸片和刀片上的傾向,以至于妨礙切割過程。解析:besuitablefor:適合……。as在句中的意思為“因為”,等同于because。句中haveatendencyto意為“有……的傾向”。BACKPREVLesson6PressProcessandProductApplicationsPressworkingincludesawidevarietyofchiplessprocessesbywhichworkpiecesareshapedfromrolledmetalsheets.Ageneralterm,stamping,isusedalmostinterchangeablywithpressworking.Stampingsareproducedbythedownwardstrokeofaraminamachinecalledapress.Theramisequippedwithspecialpunchesandmovestowardandintoadieblock,whichisattachedtoarigidbed.Thepunchesandthedieblockassemblyaregenerallyreferredtoasa“dieset"or,moresimply,asthe“die".Pressworkingoperationsareusuallycold-workedatroomtemperatureorinsomecasesBACKNEXTLesson6PressProcessandProductApplicationshot-workedatanelevatedtemperaturethatdoesnotexceedtheannealingtemperatureofthemetal.Partsproducedbypressworkingoperationscanbeassmallasashoeeyeletoraslargeastheendofafreightcar.Comparedtoothermetalworkingprocesses,pressworkingtechniquesofferanalmostunlimitedchoiceofmetalsanddesignversatilityandcanbeproducedinextremelylargequantities.Metalstampingsarelightweight,strong,andhaveasuperiorstrength-to-weightratio.Itisestimatedthattheaveragehouseholdcontainsproductsinwhichthereareover100000pressworkeditems.BACKPREVNEXTLesson6PressProcessandProductApplicationsSkillfuldesignersareoftenabletoredesignpartspreviouslymadebyforgingorbycasting,withsignificantsavingsintime,labor,andmaterials.Becauseitispracticaltoproducepartstocloselimitsofaccuracy,interchangeabilityisassured.Pressworkedpartsareusedforinternalcomponentsonbusinessmachines,machinetools,householdequipment,aircraftandsmallengines,andforlocks,variousotherhardwareitems,andcountlessotherfunctionalapplications.Itisestimatedthatapproximatelyhalftheweightofanautomobileconsistsofpressworkedparts:FormedpartsarewidelyusedascontainersofBACKPREVNEXTLesson6PressProcessandProductApplicationsvariouskinds,rangingfromhouseholdpotsandpans,topails,buckets,andbins.Sheet-metalformsarealsowidelyusedforheating,exhaust,andventilatingequipment,medicalandfoodprocessingequipment,forbuildingsandstructures,householdappliances(stoves,refrigerators,freezers,washers,anddryers),bathroomandplumbingandelectricalarticles,highwayvehicles,farmequipment,officefurniture,andformanyotherapplicationstoonumeroustomention.BACKPREVNEXTLesson6PressProcessandProductApplicationsNotes:1.Pressworkingincludesawidevarietyofchiplessprocessesbywhichworkpiecesareshapedfromrolledmetalsheets.譯文:沖壓加工包括多種多樣的無屑加工,軋制的金屬板料通過無屑加工后成形為零件。解析:avarietyof=kindsof多種多樣的shape:成形,做成某種形狀;對……有重大影響。2.Theramisequippedwithspecialpunchesandmovestowardandintoadieblock,whichisattachedtoarigidbed.BACKPREVNEXTLesson6PressProcessandProductApplications譯文:滑塊上裝有專門的凸模向裝在固定的工作臺上的凹槽運動。解析:beequippedwith配備有whichisattachedtoarigidbed是定語從句,修飾中心詞adieblock。3.Thepunchesandthedieblockassemblyaregenerallyreferredtoasa“dieset"or,moresimply,asthe“die".譯文:這些凸模和凹模裝配組件-般被稱為“模組”,或者更簡單地被稱為“沖?！?。解析:referto:提及,談到;與……有關(guān);參考。4.Pressworkingoperationsareusuallycold-workedatroomtemperatureorinsomecaseshot-workedatanBACKPREVNEXTLesson6PressProcessandProductApplicationsel