模具專業(yè)英語（第3版）PPT完整全套教學(xué)課件

Lesson1

WhatisDiesandMolds全套PPT課件TABLEOFCONTENT

1Passage2NewWordsandExpressions3Notes4ReadingMaterialLesson1WhatisDiesandMoldsWhatisadieoramold?Adieoramoldisahollowed-outblockthatisfilledwithaliquidlikeplastic,glass,metal,orceramicrawmaterials.Theliquidhardensorsetsinsidethemold,adoptingitsshape.Amoldistheoppositeofacast(seecasting).Onehalfofabronzemoldforcastingasocketedspearhead,foundatEastPennard,England.Datedtotheperiod1400～1000BC,itiswithoutparallels(Figure1-1).

什么是模具或鑄模呢？模具或鑄模是一個(gè)充滿了如塑料、玻璃、金屬或陶瓷原料液體的中空體。液體在模具內(nèi)變硬并固定成形。鑄模是鑄件的對(duì)稱物（見鑄造）。在英格蘭的東潘納德發(fā)現(xiàn)了用于鑄造矛頭的一半青銅模具，其形狀為槽形，時(shí)間可追溯到公元前1400年至公元前1000年，此模具不帶有平行線（圖1-1）。

Figure1-1Onehalfofabronzemold

forcastingasocketedspearhead圖1-1鑄造矛頭的青銅模具Lesson1WhatisDiesandMoldsMoldingistheprocessofmanufacturingbyshapingpliablerawmaterialusingarigidframeormodelcalledapattern.Themanufacturerwhomakesthemoldsiscalledmoldmaker.Areleaseagentistypicallyusedtomakeremovalofthehardened/setsubstancefromthemoldeasier.

成型是指通過穩(wěn)固的框架或模型使易變形原材料成型的過程。制造模具的制造商被稱為模具制造商。為了便于從模具中取出變硬的物體或材料，經(jīng)常使用脫模劑。Lesson1WhatisDiesandMolds

模具至少可分成兩部分（被稱為型芯和型腔）以使零件取出；一般來說，零件的形狀必須使其不會(huì)卡死在模型中。例如，物體的邊通常不與取出物體的方向平行（取出物體的方向是型芯和型腔彼此分開的方向）。兩個(gè)方向之間略帶角度；仔細(xì)檢查大多數(shù)家用塑料制品都會(huì)采用這方面設(shè)計(jì)，我們稱之為拔模斜度。桶形零件在冷卻時(shí)易于收縮至型芯處，同時(shí)在拉走型腔后，這些零件通常需用手取出。零件在成型后可以很容易地焊接在一起，并形成了根本不能設(shè)計(jì)成一個(gè)模具的中空體（像水壺或玩具頭部）。

Moldsseparateintoatleasttwohalves(calledthecoreandthecavity)topermittheparttobeextracted：ingeneraltheshapeofapartmustbesuchthatitwillnotbelockedintothemold.Forexample,sidesofobjectstypicallycannotbeparallelwiththedirectionofdraw(thedirectioninwhichcoreandcavityseparatefromeachother).Theyareangledslightly；examinationofmosthouseholdobjectsmadefromplasticwillshowthisaspectofdesign,knownasdraft①.Partsthatare“bucket-liket”tendtoshrinkontothecorewhilecoolingand,afterthecavityispulledaway,aretypicallyejectedusingpins.Partscanbeeasilyweldedtogetheraftermoldinglowforahollowpart(likeawaterjugordoll’shead)thatcouldn’tphysicallybedesignedasonemold.Lesson1WhatisDiesandMoldsMorecomplexpartsareformedusingmorecomplexmolds,whichmayrequiremoveablesections,calledslides,whichareinsertedintothemoldtoformparticularfeaturesthatcannotbeformedusingonlyacoreandacavity,butarethenwithdrawntoallowtheparttobereleased.Somemoldsevenallowpreviouslymoldedpartstobere-insertedtoallowanewplasticlayertoformaroundthefirstpart.Traditionally,moldshavebeenveryexpensivetomanufacture；therefore,theywereusuallyonlyusedinmassproductionwherethousandsofpartsarebeingproduced.

更為復(fù)雜的零件需使用更為復(fù)雜的模具形成，這些模具可能需具有被稱為滑塊的可移動(dòng)部分，滑塊被插入到模具中，形成特殊的特征，這些特征不能只用型芯和型腔成型，但是滑塊隨后被抽出以使零件松開。有些模具甚至可使以前已定型的零件重新插入，這樣一個(gè)新的塑料層就會(huì)形成在第一個(gè)零件周圍。從傳統(tǒng)生產(chǎn)上而言，制造模具已非常昂貴；因此，它們通常用于生產(chǎn)數(shù)以千計(jì)零件的生產(chǎn)線進(jìn)行批量生產(chǎn)。Lesson1WhatisDiesandMolds模具自動(dòng)化

模具可用手動(dòng)、半自動(dòng)或全自動(dòng)方式操作。模具以手動(dòng)方式操作，就是要求操作者完全把模具從壓床上拆除下來，然后拆開它并將已定型的零件拆除下來。以手動(dòng)方式操作的模具用于小批量（1～500個(gè)）零件的加工，或用于具有側(cè)向分型、螺紋或其他復(fù)雜特征的零件加工。具有較長(zhǎng)的加工周期（2～5分鐘或更長(zhǎng)時(shí)間），從本質(zhì)上而言，此加工方式屬勞動(dòng)密集型加工。

MoldAutomationMoldscanbehandoperated,semi-automaticorfullyautomatic.Handoperatedmoldsrequireanoperatortophysicallyremovethemoldfromthepressanddisassembleittoremovethemoldedpart.Theyareusedforverysmallquantities(1～500parts)orpartsthathaveundercuts,threadsorothercomplicatedfeatures.Theyhavelongoperatingcycles(2～5minutesormore)andbynaturearelaborintensivetooperate.Lesson1WhatisDiesandMolds

半自動(dòng)方式操作的模具通常安裝在壓床上，并要求操作者只執(zhí)行加工周期的特定操作（即，拆除型芯、插入零件、從側(cè)向分型中取出零件）。在用于制?；蛟诩庸ご罅苛慵豢紤]拖芯、凸輪或旋松裝置的費(fèi)用時(shí)，這種方式是很劃算的。這種加工方式的周期接近模具自動(dòng)方式操作的周期，但是所需成本也接近。

Semi-automaticmoldsaretypicallymountedinthepressandrequireanoperatoronlytoperformaspecificoperationofthecycle(i.e.,removeacore,placeaninsert,removethepartfromanundercut).Theycanbeverycosteffectiveforinsertmoldingorwhenquantifiesdonotallowfortheexpenseofcorepulls,camsorunscrewingdevices.“Machinecycletimescanapproachatofautomaticmolds,but-socantheircost.Lesson1WhatisDiesandMoldsFullyautomaticmoldsrunwithnooperator.Theymayutilizeavarietyofmechanicaldevicestofacilitatepartremovalsuchasmoldsweeps,airblasts,spruepickersorrobots.Theymaycontaincorepulls,camstoremoveundercuts,multipleplates,hotrunnerorinsulatedrunnersystems,unscrewingdevicesorany,numberofdevicesandtechniquestoimproveefficiency(Figure1-2).Partsarenormallyfinishedasmoldedwithnopostoperations,beyondvalueaddedoperationsrequired.

全自動(dòng)方式下，模具無需操作者來操作。這種方式可利用各種機(jī)械設(shè)備使拆除零件變得容易，如模具刮模器、氣噴裝置、澆注口清洗機(jī)或機(jī)器人。這種方式包括可拉動(dòng)的型芯、可移動(dòng)側(cè)向分型的凸輪、多層模板、熱的或絕緣的澆道系統(tǒng)、旋松裝置或任何型號(hào)的設(shè)備和技術(shù)以提高效率（圖1-2）。

除非有所需的附加值操作，零件通常無需人員操作進(jìn)行定型。

Figure1-2Typicalmoldbaseshowingthevariouscomponents圖1-2典型模具基本結(jié)構(gòu)組成Lesson1WhatisDiesandMoldsMoldMaterialsMoldsaretypicallyconstructedfromhardenedsteeloraluminium.Thechoiceofmaterialtobuildamoldisprimarilyeconomics.Steelmoldsgenerallycostmoretoconstruct,buttheirlongerlifespanwilloffsetthehigherinitialcostoverahighernumberofpartsmadeinthemoldbeforewearingout.

Aluminiummoldscancostsubstantiallyless,andwhendesignedarmmachinedwithmodemcomputerizedequipment,canbeeconomicalformoldinghundredsoreventensofthousandsofparts.②模具材料

模具通常由硬化鋼或鋁材構(gòu)成。構(gòu)成模具所需材料的選擇從根本上來說是個(gè)經(jīng)濟(jì)學(xué)問題。一般來說鋼材料構(gòu)成的模具成本較高，但是鋼材料模具在磨損前可制成大量零件，它們的較長(zhǎng)使用壽命將抵消最初的較高成本。鋁材模具成本會(huì)大大地減少，當(dāng)用現(xiàn)代計(jì)算機(jī)設(shè)備設(shè)計(jì)和加工時(shí)，用鋁材模具成型數(shù)以百計(jì)甚至是數(shù)以萬計(jì)的零件會(huì)很經(jīng)濟(jì)。

Lesson1WhatisDiesandMolds?

die[dai]n.模具?

mold[mEuld]n.模具，模?

hollowed-outadj.中空的?

ceramic[sI'rAmIk]n.陶瓷?

harden['hB:dn]v.硬化，淬火?

opposite['CpEzit]n.對(duì)稱物

?

cast[kB:st]n.鑄件，鑄造

v.鑄造

?

bronze[brCnz]n.青銅?

socket['sCkit]n.槽v.有槽?

spear[spiE]n.矛?

parallel['pArElel]n.平行線，

?

molding['mEuldiN]n.成型?

pliable['plaiEbl]adj.柔韌的?

rigid['ridVid]adj.穩(wěn)固的?

frame[freim]n.架

NewWordsandExpressions?pattern[5pAtEn]n.仿制

?moldmakern.模具制造商

?agent['eidVEnt]n.代理人?mold[mEuld]n.模型，模具?core[kC:]n.型芯，模芯?cavity['kAviti]n.型腔，模腔?extract[iks'trAkt]v.取出?aspect['Aspekt]n.方面?design[di'zain]n.設(shè)計(jì)

?draft[drB:ft]n.拔模斜度?bucket-like['bQkit]adj.桶形的?shrink[FriNk]v.收縮?eject[I'dVekt]v.取出?pin[pin]n.銷?weld[weld]v.焊接

n.黏結(jié)

?physically['fIzIk(E)lI]adv.根本地?Lesson1WhatisDiesandMolds?moveable['mu:vEbl]adj.可移動(dòng)的?slide[slaid]n.滑座，滑塊?withdraw[wiT'drC:]v.抽出?release[ri'li:s]v.松開?automation[C:tE'meiFEn]n.自動(dòng)化?semi-automatic['semi;C:tE'mAtik]adj.半自動(dòng)的?remove[ri'mu:v]v.移動(dòng)，切削

NewWordsandExpressions?press[pres]n.壓床?disassemble[;disE'sembl]v.拆開?undercut['QndEkQt]n.側(cè)向分型?thread[Wred]n.螺紋

?intensive[in'tensiv]adj.密集的

?cam[kAml]n.凸輪

?unscrew['Qn'skru:]v.旋松

?mechanical[mi'kAnikl]adj.機(jī)械的?facilitate[fE'siliteit]v.使容易Lesson1WhatisDiesandMolds?blast[blB:st]n.噴?sprue[spru:]n.澆注

?picker['pikE]n.清洗機(jī)?sweep[swi:p]n.刮模器?runner['rQnE(r)]n.澆道?insulate['insjuleit]v.絕緣?efficiency[i'fiFEnsi]n.效率?construct[kEn'strQkt]v.構(gòu)成?aluminium[;Alju:'minjEm]n.鋁?offset['fset]v.抵消

NewWordsandExpressions?substantially[sEb'stAnF(E)lI]adv.充分地?economical[;i:kE'nCmikEl]adj.經(jīng)濟(jì)的?rawmaterial原料?datedto追溯到

?releaseagent脫模劑?beparallelwith與……平行?bedesignedas被設(shè)計(jì)為?massproduction批量生產(chǎn)?bynature從本質(zhì)上而言

?costeffective劃算的?allowfor考慮?cycletime周期

?wearout磨損Lesson1WhatisDiesandMoldsLesson2

TheInjectionMoldingandMachineTABLEOFCONTENT

1Passage2NewWordsandExpressions3Notes4ReadingMaterialLesson1WhatisDiesandMolds1．注塑模

盡管成型某些熱固性材料的方法取得了一定進(jìn)步，但注塑模主要（還是）用來生產(chǎn)熱塑性塑件。（這主要是因?yàn)椋峁绦运芰先垠w在很短的時(shí)間內(nèi)就會(huì)固化和硬化，在從料斗向模具型腔注入熱固性塑料熔體的過程中，也會(huì)出現(xiàn)這種情況，這個(gè)問題一直非常難解決。

1.TheInjectionMoldingInjectionmoldingisprincipallyusedfortheproductionofthethermoplasticparts,althoughsomeprogresshasbeenmadeindevelopingamethodforinjectionmoldingsomethermosettingmaterials.Theproblemofinjectingameltedplasticintoamoldcavityfromareservoirofmeltedmaterialhasbeenextremelydifficulttosolveforthermosettingplasticswhichcureandhardenundersuchconditionswithinafewminutes①.Lesson2TheInjectionMoldingandMachineNote①句中的ofinjectingameltedplasticintoamoldcavityfromareservoirofmeltedmaterial介詞短語作后置定語修飾theproblem，whichcureandhardenundersuchconditionswithinafewminutes定語從句作后置定語修飾thermosettingplastics。Theprincipleofinjectionmoldingisquitesimilartothatofdie-casting.Theprocessconsistsoffeedingaplasticcompoundinpowderedorgranularformfromahopperthroughmeteringandmeltingstagesandtheninjectingitintoamold②.

注塑成型原理和鑄造十分相似。注塑成型的工藝過程包括：首先把料斗中的粉狀或粒狀的塑料混合物依次輸送到計(jì)量區(qū)和熔化區(qū)，然后再注射到模具型腔中。Lesson2TheInjectionMoldingandMachineNote②句中consistof意為：由……組成，由and連接的三個(gè)動(dòng)名詞短語作of的賓語。Afterabriefcoolingperiod,themoldisopenedandthesolidifiedpartejected.Injection-moldingmachinescanbearrangedformanualoperation,automaticsingle-cycleoperation,andfullautomaticoperation.Theadvantageofinjectionmoldingare:(i)ahighmoldingspeedadaptedformassproductionispossible;(ii)thereisawidechoiceofthermoplasticmaterialsprovidingavarietyofusefulproperties;(iii)itispossibletomoldthreads,undercuts,sideholes,andlargethinsections.Lesson1WhatisDiesandMolds經(jīng)過短時(shí)冷卻后，開模，推出成型塑件。注塑機(jī)分為手動(dòng)、半自動(dòng)及全自動(dòng)操作。注塑模具有以下優(yōu)點(diǎn)：（i）較高的成型速度使大批量生產(chǎn)成為可能；（ii）為成型具有不同使用性能的熱塑性材料提供了較寬的選擇；（iii）可以成型帶有螺紋的塑件、側(cè)向凹陷的塑件、帶有側(cè)孔的塑件以及較大的薄壁件。2.TheInjection-moldingMachineSeveralmethodsareusedtoforceorinjectthemeltedplasticintothemold.Themostcommonlyusedsysteminthelargermachinesisthein-linereciprocatingscrew,asshowninFigure2-1.2．注塑機(jī)熔融塑料注入模具中通常有幾種方式。在大型注塑機(jī)上常采用往復(fù)螺桿式的注入方式，如圖2-1所示。

Lesson2TheInjectionMoldingandMachineFigure1-2Thereciprocorting-screwinjection-moldingsystem圖2-1注塑系統(tǒng)螺桿同時(shí)具有注射和塑化的功能。樹脂原料進(jìn)入旋轉(zhuǎn)的螺桿時(shí)，要經(jīng)過圖示的三個(gè)區(qū)域：喂入?yún)^(qū)、壓實(shí)區(qū)和計(jì)量區(qū)。經(jīng)過喂入?yún)^(qū)后，為壓實(shí)樹脂原料，螺桿螺旋部分的深度逐漸降低，同時(shí)傳遞樹脂原料間因剪切作用而產(chǎn)生的熱量，使原料呈半流動(dòng)狀態(tài)。在計(jì)量區(qū)，螺缸表面的加熱裝置對(duì)熔體進(jìn)一步加熱。

Thescrewactsasacombinationinjectionandplasticizingunit.Astheplasticisfedtotherotatingscrew,itpassesthroughthreezonesasshown:feed,compression,andmetering.Afterthefeedzone,thescrew-flightdepthisgraduallyreduced,forcingtheplastictocompress.Theworkisconvertedtoheatbyshearingtheplastic,makingitasemifluidmass.Inthemeteringzone,additionalheatisappliedbyconductionfromthebarrelsurface.Lesson1WhatisDiesandMolds當(dāng)熔體充滿螺桿前部區(qū)域時(shí)，螺桿在熔體壓力的作用下后退，觸動(dòng)限位開關(guān)使液壓缸工作，在液壓力的作用下推動(dòng)螺桿向前運(yùn)動(dòng)，將熔融塑料注射到閉合的模具型腔中。防倒流閥能夠阻止受壓熔體倒流進(jìn)螺桿的螺旋區(qū)。

Asthechamberinfrontofthescrewbecomesfilled,itforcesthescrewback,trippingalimitswitchthatactivatesahydrauliccylinderthatforcesthescrewforwardandinjectsthefluidplasticintotheclosedmold③.Anrefluxvalvepreventsplasticunderpressurefromescapingbackintothescrewflights.Lesson2TheInjectionMoldingandMachineNote③句中as引導(dǎo)的時(shí)間狀語從句，thatactivatesahydrauliccylinderthatforcesthescrewforwardandinjectsthefluidplasticintotheclosedmold為限制性定語從句修飾alimitswitch，thatforcesthescrewforwardandinjectsthefluidplasticintotheclosedmold修飾ahydrauliccylinder。Theclampingforcethatamachineiscapableofexertingispartofthesizedesignationandismeasuredintons.Arule-of-thumbcanbeusedtodeterminethetonnagerequiredforaparticularjob.Itisbasedontwotonsofclampforcepersquareinchofprojectedarea.Iftheflowpatternisdifficultandthepartsarethin,thismayhavetogotothreeorfourtons.Lesson1WhatisDiesandMolds

注塑機(jī)的鎖模系統(tǒng)所提供的鎖模力由（塑件在分型面的投影）尺寸決定，鎖模力以噸為單位。通?？拷?jīng)驗(yàn)來決定塑件所需要的鎖模力總噸數(shù)，一般在塑件投影面積上每平方英寸需要作用兩噸鎖模力。如果熔體流動(dòng)困難或塑件較薄，鎖模力應(yīng)提高到三噸到四噸。

許多往復(fù)螺桿式注塑機(jī)能生產(chǎn)熱固性塑料。以前，熱固性塑料由擠出模具或傳遞模具生產(chǎn)。熱固性塑料熔體在模具內(nèi)固化或發(fā)生聚合反應(yīng)，并在溫度為375℃～410℃范圍內(nèi)推出。熱塑性塑料熔體必須在模具內(nèi)冷卻成型，以保證推出時(shí)不發(fā)生變形。這種熱固性循環(huán)速度很快。當(dāng)然，生產(chǎn)熱塑性塑件時(shí)，模具必須被加熱，而不是冷卻。

Manyreciprocating-screwmachinesarecapableofhandingthermosettingplasticmaterials.Previouslythesematerialswerehandledbycompressionortransfermolding.Thermosettingmaterialscureorpolymerizeinthemoldandareejectedhotintherangeof375℃～410℃.Thermoplasticpartsmustbeallowedtocoolinthemoldinordertoremovethemwithoutdistortion.Thusthermosettingcyclescanbefaster.Ofcoursethemoldmustbeheatedratherthanchilled,aswiththermoplastics.

Lesson1WhatisDiesandMolds?injectionmolding注射模

?principally['prinsipli]adv.主要地?thermoplastic[;0=:m='pl7stik]n.熱塑性，熱塑性塑料

?thermosetting[;0=:m=u'seti9]n.熱固性?plastic['pl7stik;pl1:stik]n.塑膠，塑料

?melted[meltid]vt.（使）熔化，使軟化?cavity['k7viti]n.型腔

?reservoir['rez=vw1:]n.容器，儲(chǔ)存器?extremely[iks'tri:mli]adv.極端地，非常地

?principle['prins=pl]n.法則，原則，原理?die-casting壓力鑄造

?compound['k6mpaund]n.混合物，復(fù)合的，混合?powdered['paud=d]adj.弄成粉的，粉狀的

?granular['Gr7njul=]adj.由小粒而成的，粒狀的?hopper['h6p=]n.加料漏斗

NewWordsandExpressions?metering['mi:t=ri9]vt.測(cè)量（法），計(jì)［配］量，測(cè)定?eject[i'd3ekt]vt.逐出，噴射

?solidify[s='lidifai]vt.（使）凝固，（使）團(tuán)結(jié)?manual['m7nju=l]adj.手的，手動(dòng)的，手工的

?automatic[;6:t='m7tik]adj.自動(dòng)的，機(jī)械的?property['pr6p=ti]n.性質(zhì)，特性

?thread[0red]n.螺紋?undercut['2nd=k2t]n.側(cè)向分型，底切

?reciprocatingscrew往復(fù)螺桿?plasticize['pl7stisaiz]vt.使成可塑體

?compression[k=m'pre5(=)n]n.濃縮，壓縮?screw-flight螺桿的螺紋

?convert[k=n'v=:t]vt.使轉(zhuǎn)變，轉(zhuǎn)換?shear[5i=]vt.剪，剪切

?semifluid[;semi'flu:id]adj.半流質(zhì)，半流質(zhì)的?Lesson1WhatisDiesandMolds?barrel['b7r=l]n.桶

?chamber['t5eimb=]n.室，房間?trip[trip]vt.松開棘爪而開動(dòng)；使跳閘；切斷

?switch[swit5]n.開關(guān)，轉(zhuǎn)換，轉(zhuǎn)變?hydraulic[hai'dr6:lik]adj.水力的，水壓的

?cylindervalve氣缸閥?clampingforce鎖緊力

?exert[iG'z=:t]vt.盡（力），施加（壓力）

NewWordsandExpressions?rule-of-thumb單憑經(jīng)驗(yàn)的方法

?transfermolding傳遞模塑法，轉(zhuǎn)送成形?polymerize['p6lim=raiz]vt.（使）聚合

?distortion[dis't6:5=n]n.扭曲，變形?plunger['pl2nd3=]n.柱塞

?spurt[sp=:t]vt.（液體等）噴射，噴出?sprue[spru:]n.澆口，熔渣

?optimum['6ptim=m]adj.最適宜的?foam[f=um]vt.起泡沫Lesson1WhatisDiesandMoldsLesson3MoldMaterialsTABLEOFCONTENT

1Passage2NewWordsandExpressions3Notes4ReadingMaterialLesson3MoldMaterials

根據(jù)各種不同工藝方法的工藝參數(shù)和不同產(chǎn)品的生產(chǎn)運(yùn)行時(shí)間（即要加工的成品數(shù)量），模具必須要滿足不同的要求。因此，模具使用材料多樣，包括像紙梗火柴、石膏這樣的奇異材料，并不足為奇。

Dependingontheprocessingparametersforthevariousprocessingmethodsaswellasthelengthoftheproductionrun,i.e.,thenumberoffinishedproductstobeproduced,moldsmustsatisfyagreatvarietyofrequirements．Itisthereforenotsurprisingthat,moldscanbemadeofaverybroadspectrumofmaterials,includingsuchexoticmaterialsaspapermatchandplaster．

Lesson3MoldMaterials然而，由于大部分加工過程要求高壓并經(jīng)常伴有高溫，到目前為止，金屬仍然是最重要的模具材料，其中鋼是主要的金屬材料。有趣的是，在許多情況下，選擇哪種模具材料不僅要考慮材料的特性和最佳的性價(jià)比，還要考慮模具的制造方法，因?yàn)樗鼈儠?huì)影響整體設(shè)計(jì)。

However,becausemostprocessesrequirehighpressures,andoftencombinedwithhightemperatures,metalsstillrepresentbyfarthemostimportantmaterialgroup,withsteelbeingthepredominantmetal．Itisinterestinginthisregardthat,inmanycases,theselectionofthemoldmaterialisnotonlyaquestionofmaterialpropertiesandanoptimumprice-to-performanceratiobutalsothemethodsusedtoproducethemold,andthustheentiredesigncanbeinfluenced.Lesson3MoldMaterialsAtypicalexamplecanbeseeninthechoicebetweencastmetalmoldsandmachinedmolds,withtheirverydifferentcoolingsystems．Inaddition,theproductiontechniquecanalsohaveaneffect.Forinstance,itisoftenreportedthat,forthesakeofsimplicity,aprototypemoldisfrequentlymachinedfromsolidstockwiththeaidofthelatesttechnologysuchascomputeraideddesign(CAD)andcomputerintegratedmanufacturing(CIM).Incontrasttothis,previouslyusedmethodsbasedontheuseofpatterns,theuseofCADandCIMoftenrepresentsthemoreeconomicalsolutiontoday,notonlybecausethisproductioncapabilityisavailablein-housebutalsobecausewithsomeothertechniqueanorderwouldhavetobeplacedwithanoutsidesupplier.一個(gè)典型的例子可以說明鑄造金屬模和機(jī)械模的冷卻系統(tǒng)區(qū)別很大。另外，生產(chǎn)技術(shù)也有影響。例如，經(jīng)常報(bào)道說為了簡(jiǎn)單起見，固態(tài)坯料常用像計(jì)算機(jī)輔助設(shè)計(jì)（CAD）和計(jì)算機(jī)集成制造（CIM）這樣的最新技術(shù)制造成原型模具。與以前制造模型的方法相比，CAD和CIM的應(yīng)用代表了當(dāng)今更為經(jīng)濟(jì)的制造方法，不僅因?yàn)閮?nèi)部生產(chǎn)能力可以利用，還因?yàn)槿舨捎闷渌に嚰夹g(shù)，訂單必然會(huì)落入廠外供應(yīng)商手里。

Lesson3MoldMaterials總之，盡管高級(jí)材料也常被使用，但是模具制造通常還是使用標(biāo)準(zhǔn)材料。例如，新型高性能的材料（如陶瓷）幾乎還沒被使用?？赡艿南嚓P(guān)事實(shí)是，陶瓷在非常高的溫度下仍能保持好的特性，但這對(duì)于模具來說并不需要，何況陶瓷還有不好的特性，如抗拉強(qiáng)度低、熱導(dǎo)性差等。模具制造中燒結(jié)材料的使用還是有限的。與多孔透氣的燒結(jié)材料相比，粉末冶金和熱等靜壓加工的現(xiàn)代材料和零件則更少使用。

Overall,althoughhigh-gradematerialsareoftenused,asarule,standardmaterialsareusedinmoldmaking.New,high-performancematerials,suchasceramics,forinstance,arealmostcompletelyabsent.Thismayberelatedtothefactthattheirdesirablecharacteristics,suchasconstantpropertiesuptoveryhightemperature,arenotrequiredinmolds,whereastheirnegativecharacteristic,e.g.,lowtensilestrengthandpoorthermalconductivity.Havingaclearrelationtoceramics,sinteredmaterial,isfoundinmoldmakingonlytoalimiteddegree.Thisreferslesstothemodernmaterialsandcomponentsproducedbypowdermetallurgy,andpossiblybyhotisostaticpressing,thantosinteredmetalsinthesenseofporous,air-permeablematerials.Lesson3MoldMaterialsRemovalofairfromthecavityofamoldisanecessarywithmanydifferentprocessingmethods,andithasbeenproposedmanytimesthatthiscanbeaccomplishedusingporousmetallicmaterials.①Theadvantagesoverspeciallyfabricatedventingdevices,particularlyinareaswheremeltflowfrontsmeet,i.e.,atweldlines,areasobviousastheproblemareas：Ontheonehand,preventingthetextureofsuchsurfacesfrombecomingvisibleonthefinishedproduct,andontheotherhand,preventingthemicroporesfromquicklybecomingcloggedwithresidues.

在許多不同的成型方法中，都必須將型腔中的氣體排除，人們已經(jīng)多次嘗試使用多孔金屬材料來排氣。專門制造的排氣裝置位于熔融物料前鋒相遇的地方，即熔接痕處。這個(gè)極可能出現(xiàn)問題的地方優(yōu)勢(shì)顯著：一方面，預(yù)防成品在表面形成看得見的痕跡；另一方面，預(yù)防微孔很快被殘?jiān)氯?。Lesson3MoldMaterials此時(shí)，人們對(duì)由于采用這種材料而引起的有關(guān)全新模具設(shè)計(jì)和制造工藝的可能性也產(chǎn)生了興趣。燒結(jié)材料的排氣、冷卻和脫模工序的說明如圖3-1所示。

Itisalsointerestinginthiscasethatcompletelynewpossibilitieswithregardtomolddesignandprocessingtechniqueresultedfromtheuseofsuchmaterials.Theprocessstepsofventing,cooling,andejectinginrelationtotheuseofsinteredmetalscanbebestillustratedwiththeaidofthesketchesshowninFigure3-1.

Figure3-1Microporousmetalejectinginamold圖3-1多孔金屬注射進(jìn)模具Lesson3MoldMaterialsVentingoftheedge-gatedcavityusedtoproduceacup-shapedproductwithacomplexbottomwouldrequireagreatdealoftechnicalefforttoprovideguaranteedremovaloftheairfromthebottomregion.②Byusingamicroporousmaterialforthecoreandcavityhalves,noadditionalmeasuresforventingarerequired.Moreover,becauseventingtakesplaceovertheentiresurfaceareaofthecavity,fillingofthecavitycanoccurfaster,andthereis,inprinciple,freedominselectingthelocationofthegate.用側(cè)澆口成型帶有復(fù)雜底部形狀的杯狀制品時(shí)，如何保證將底部的氣體順利排出，其技術(shù)難度是非常大的。用多孔材料做型芯和型腔，不需要其他的排氣措施。而且因?yàn)橥耆谛颓槐砻媾艢?，所以能很快填充型腔，原則上可自由選擇澆注口的位置。

Lesson3MoldMaterials從狹長(zhǎng)的型芯中散去大量熱量是非常困難的。既然這樣，讓散布的冷空氣通過型芯微孔，從而加劇冷卻，以縮短生產(chǎn)周期。Itisparticularlydifficulttoremovethenecessaryamountofheatinregionswithlong,narrowcores.Inthiscase,itispossibletodistributecoldgasviathesystemofmicroporesinthecoreandinthiswayintensifythecooling,withthepossibleresultofachievingashortercycletime.③Note③“inthiscase”譯為“既然這樣”。該句為主語從句，“itispossible”中的“it”是形式主語，真正的主語是“distributecoldgasviathesystemofmicroporesinthecoreandinthiswayintensifythecooling”。Lesson3MoldMaterialsImprovedtemperatureuniformityoverthemoldsurfacecanbeanotherbeneficialsideeffect.Itisalsopossible,incombinationwithothermeans(ejectors,stripper：rings)orevenwithoutthem,toejecttheproductbyinjectinggasathighpressureintothecorehalfofthemold.Inthisway,theriskofejectormarksisreducedoreliminated,andthereisnoneedtoovercomeavacuumduringejection.另一附帶的好處就是模具表面的溫度均勻性提高了?？梢越Y(jié)合其他方法（頂出器、脫模圈），或不用其他方法而直接在型芯中注入高壓氣體，從而推出產(chǎn)品。這樣就可以減少或消除頂出器的痕跡，且注射過程中無須克服真空問題。

Lesson3MoldMaterials?spectrum['spektr=m]n.列，范圍；光譜?exotic[iG'z6tik]adj.奇異的，外來的?byfar（修辭比較級(jí)、最高級(jí)）……得多，最……，到目前為止?predominant[pri'd6min=nt]adj.占優(yōu)勢(shì)的，主要的?materialproperty材料性能?optimum['6ptim=m]adj.最適宜的?price-to-performanceratio性價(jià)比?prototypemold原型模具?computeraideddesign計(jì)算機(jī)輔助設(shè)計(jì)?computerintegratedmanufacturing計(jì)算機(jī)集成制造?incontrastto...和……形成對(duì)比?tensilestrength抗拉強(qiáng)度?sinteredmaterial燒結(jié)材料?component[k=m'p=un=nt]n.零件，組件?metallurgy[me't7l=d3i]n.冶金學(xué)，冶金術(shù)?isostatic[;ais=u'st7tik]adj.均衡的

NewWordsandExpressions?porous['p6:r=s]adj.多孔的，能滲透的?air-permeablematerial透氣性材料?cavity['k7viti]n.型腔?meltflowfront熔融物料前鋒?weldline熔接痕?micropore['maikr=p6:]n.微孔?clog[kl6G]v.堵塞，障礙?withregardto關(guān)于……?resultfrom由……造成（引起）的?venting['ventI9]n.通風(fēng)，排氣?edge-gatedcavity側(cè)（邊緣）澆口式型腔?temperatureuniformity溫度均勻性?ejector[i'd3ekt=]n.頂出器?stripperring脫模圈?ejectormark頂出痕跡?eliminate[i'limineit]vt.消除，清除?vacuum['v7kju=m]n.真空Lesson3MoldMaterialsLesson4SelectionoftheSteelTABLEOFCONTENT

1Passage2NewWordsandExpressions3Notes4ReadingMaterial

塑料成型工藝的發(fā)展和不同成型性能導(dǎo)致不同的負(fù)荷，這些不僅在設(shè)計(jì)時(shí)必須考慮到，而且在選擇所需的模具材料時(shí)也必須考慮到。鋼具有理想的性能，因?yàn)樗男阅芸梢酝ㄟ^加入的合金元素、特定的生產(chǎn)工藝及熱處理進(jìn)行改善，以成為鋼的有利性能，從而滿足使用壽命長(zhǎng)及經(jīng)濟(jì)的加工。

Theprocessdevelopedformoldingplasticsandthedifferentprocessingpropertiesoftheplasticsleadtodifferentloads,whichmustbetakenintoconsiderationnotonlyinthedesignbutalsointheselectionofthematerialsrequiredformolds．Steelhastheidealqualifications,becauseitspropertiescanbemodifiedbyalloyingelements,specialproductionprocesses,andheattreatment,anditcanbeadjustedtothealreadyadvantageouspropertiesofthesteelsandtherebysuittherequirementsforlongservicelifeandeconomicalmanufacture.

Lesson4SelectionoftheSteelThemostimportantrequirementsforthemoldsteelsare:(i)Highcompressivestrengthexpectedevenathightemperatures;(ii)Wearresistance;(iii)Greattoughness;(iv)Corrosionresistanceandgoodthermalconductivity.Also,themoldmakerexpectsthefollowingproperties:(i)Goodmachinability;(ii)Goodhobbingcapabilities(whererequired);(iii)Dimensionalstabilityduringheattreatment;(iv)Goodpolishingproperties;(v)Surfacetexturingwithoutdifficulties(whererequired).Finally,themoldsteelshouldbereadilyavailable,arequirementthatdemandsastandardizationofsizesanduniversallysuitabletypesofsteels.對(duì)模具鋼最重要的要求有以下幾點(diǎn)：（1）在高溫下高的抗壓強(qiáng)度；（2）耐磨性；（3）高的韌性；（4）耐蝕性和良好的熱導(dǎo)性。模具制造者希望模具鋼具有以下性能：（1）良好的切削加工性；（2）良好的銑削性能（如需要）；（3）熱處理過程中的尺寸穩(wěn)定性；（4）良好的拋光性能；（5）表面處理容易（如需要）。最后，模具鋼應(yīng)齊備，要求尺寸標(biāo)準(zhǔn)化并普遍適用于各類鋼材。

Lesson4SelectionoftheSteel考慮到模具材料所受到的各種壓力，可認(rèn)識(shí)到一種鋼不能滿足所有的條件。經(jīng)過多年鋼鐵生產(chǎn)者和使用者的密切合作，開發(fā)出的模具鋼可分為以下幾種：氮化鋼，表面硬化鋼，預(yù)硬鋼，完全硬化鋼，耐腐蝕鋼，馬氏體鋼，超硬材料合金。

Consideringthevariousstressestowhichthemoldmaterialissubjected,itisunderstandablethatnotallconditionscanbemetwithonegradeofsteel.Theexperienceofmanyyearsandtheclosecooperationbetweensteelproducersandconsumershaveledtothedevelopmentofmoldsteelsthatcanbedividedintothefollowinggroups:nitridingsteels,case-hardenedsteels,prehardenedsteels,fullyhardenedsteels,corrosion-resistantsteels,maragingsteels,hardmaterialalloys.①Note句中的“theexperienceofmanyyearsandtheclosecooperationbetweensteelproducersandconsumers”是這個(gè)句子的主語；“dividedinto...groups”譯為“分成了幾個(gè)組”。Lesson4SelectionoftheSteel1.NitridingSteelsNitridingsteelsarepreferredforextruders.Veryhighsurfacehardnessvaluesofatleast950HVareattainedwiththealuminum-alloyedsteels34CrAlMo5and34CrAlNi7.Becauseoflowertoughness,thedepthofthenitridedlayermustbelimited.Forthisreasonthealuminum-freenitridingsteel14CrMoV69isincreasinglyselectedforbarrelsand31CrMoV9forscrews.Thetotalservicelifeoftheextrudersmadefromaluminum-freenitridingsteelsisconsequentlylongerthanthatofthealuminum-alloyedsteels.Ingeneral,nitridingsteelsaresuppliedinalreadyquenchedandtemperedcondition.1．氮化鋼氮化鋼是擠出模的首選材料。鋁合金鋼34CrAlMo5和34CrAlNi7氮化后表面硬度值可達(dá)到至少950HV。由于氮化后韌性較低，滲氮層的深度必須加以限制?；谶@個(gè)原因，鋁氮化鋼14CrMoV69用來做管類零件，31CrMoV9用來做螺絲釘。由鋁呈自由狀態(tài)的氮化鋼制造的擠壓?？偸褂脡勖L(zhǎng)于由鋁合金鋼制造的擠壓模。一般情況下，氮化前需進(jìn)行調(diào)質(zhì)處理。

Lesson4SelectionoftheSteelNitridingsteelsareusedinmoldsonlyinspecialcases,e.g.,forverythinblades.However,becausethecorestrengthofthesesteelsislow,hotworksteelsH11andH13,whicharealsoknownfortheiruseinlightmetaldie-castingmoldconstruction,arepreferred.

氮化鋼只有在特殊情況下才用于模