陶瓷加工方式專業(yè)英語(yǔ)原文

3倉(cāng)促之作，如有紕漏，請(qǐng)自行修改！Ceramicprocessingmethods陶瓷加工方式Presentmethodsofmanufacturingceramicgreenbodiesofacomplicatedshapeonanindustriallevelincludedry-pressingwithsubsequentmachining,slipcasting,pressurecasting,andinjection castingisusedtoproducethinsheets,mainlyfortheelectronicstheseformingmethodsstartwithasuspensionwheretheceramicparticles(powders,whiskers,etc.)aremixedwithaliquidorapolymermelt,properdispersant,andpossiblyfurtheradditivessuchasbinders,plasticizers,and antifoaming agents so that a well-dispersed,nonagglomeratedceramicslurrycanbemade.從制備懸濁浮液開(kāi)頭的。陶瓷顆粒〔粉末，晶須〕和水或熔化的聚合物，分散劑和可能需要的添加劑如：黏合劑，塑化劑，去泡劑相混合來(lái)取得分散良好，沒(méi)有團(tuán)聚的漿體。Withthegrowingawarenessofthedetrimentaleffectsofdifferenttypesofheterogeneitiesonthematerialspropertiesofmainlystructuralceramics,aconceptcalledcolloidalprocessinghasbeenintroducedasausefulapproachforflawofcolloidalprocessingincluderemovaloflarge,hardagglomeratesinthestartingpowderthroughsedimentationorfiltrationofwell-dispersedsuspensionsandthedevelopmentofdesigned,orderedmixturesofseveralcomponentsthroughthemanipulationoftheinterparticleconceptsapplytomostconventionalprocessingmethods,andtheyalsocanbeusedforthedevelopmentofnewprocessingtechniques.隨著對(duì)不同類型的非均質(zhì)性的主要構(gòu)造陶瓷的材料性能不利影響的日趨生疏能夠用來(lái)進(jìn)展為處置技術(shù)。Drypressingandcoldisostaticpressing(CIPing)areprobablythemostimportantformingtechniquesforindustrialproductionofceramicbodiesareformedbypressinggranulesinafree-flowinggranulesareformedfromasuspensionusingagranulationtechnique,.,spraydryingorfreeze isanestablishedformingtechniquethathasexistedfordecadesandhasbeenusedformanyapplications,rangingfromdinnerwaretoinsulatorsandspark,therearedevelopmentsinthefieldinvolvinghigh-pressureCIPingandcyclicCIPingthatcanproducegreenbodiesofhigher majoradvantageofdrypressingisproductivity;modempressescanproduceasmanyas20partspermakespressingthemethodofchoiceformostindustrialceramicoperationsdespitetheproblemsassociatedwithdensitygradients,inhomogeneousmicrostructures,andtheneedtomachinecmplex-shapedobjects.〔CIPing〕方式能夠生產(chǎn)高密度的陶瓷生坯。干壓的主要優(yōu)勢(shì)是生產(chǎn)率;調(diào)制解調(diào)器壓力機(jī)每分鐘能夠生產(chǎn)多達(dá)20件。雖然存在與密度梯度、非均勻微構(gòu)造，和機(jī)械加工簡(jiǎn)單外形物體的相關(guān)問(wèn)題，壓制方式仍是成了大部份工業(yè)陶瓷經(jīng)營(yíng)商的首選。Allthedrain-castingtechniques.,slipcasting,pressurecasting,andcentrifugalcastinginvolveasolid-liquidseparationprocesstoformadensegreenliquidflowisdrivenbyeitheranexternalpressuregradient(slipcasting,pressurecasting)orabodyforceinacentrifugalforcefield(centrifugalcasting).Slipcastingisalow-pressurefiltrationmethodwherecapillarysuctionprovidesthedrivingforce(ontheorderof~forliquidremovalandformationofacastlayeratamoldcastingisgenerallyaslowprocess,becausethecastingratedecreasesparabolicallywiththicknessofthecastcastingwhichisanestablishedformingtechniqueinfabricationoftraditionalclay-basesceramicmaterials,suchaspotteryandsanitaryporcelain---andpressurefiltrationaremodificationsofslipcastingthathavebeendevelopedtoacceleratetheconsolidationstageandtoobtainahighergreenthesemethods,anexternalpressure(<4MPa)substantiallyhigherthanthecapillarysuctionpressureisappliedtotheceramicsuspension.程，會(huì)形成致密的坯體。液體的流淌是受一個(gè)外部壓力梯度〔注漿，壓力成型，或離心力場(chǎng)〔離心成型〕的驅(qū)動(dòng)。注漿成型時(shí)一個(gè)低壓過(guò)濾的進(jìn)程。在那個(gè)進(jìn)程中，毛細(xì)管的吸力把成型率隨著成型厚度呈拋物線下降。壓力注漿成型是成立在傳統(tǒng)的粘土陶瓷材料的制造技良，并取得較高的綠色密度。Thetraditionaldrain-castingmethodsareplaguedbysomegeneticliquidflowaffectsthesuspensionmicrostructureandtendstoorientnonsphericalconstituents,suchasstressgradientmayalsoleadtononuniformdensitiesofthegreenbodyandcausemasssegregationbecauseofdifferencesinparticlesizeanddensity.Undrained,orconstantvolume,forningmethods,suchasunjectionmolding,havethepotentialtoavoidtheaforementionedmoldingiscapableofproducingpartsofcomplexshapewithhighprecisionatrelativelyhighproductioncommonlyusedformingtechniqueisbasedonmixingoftheceramicpowderwithabindersystem(usuallyamixtureofpolymers)tocreateaviscousfeedstockandformingrhepartbyinjectingthepowder/bindermixtureintoanimpermeablemold,wherethebinderissolidified,usuallybyatemperaturemoldinghasprovedtobeanexcellentformingtechniqueforsmallerobjectsslthoughtherearepotentialproblemsrelatedtothediefillingwearofscrew-driveninjectorsforhigh-pressureinjectionmoldingcanalsoleadtometallicinclusionsandpoorreliability.Themajorproblemconfrontingjnjectionmoldingistheremovaloftheremovaloftheburnoutmustproceedataslowrate(takinguptoseveraldays)toavoidproblemswithslumpingandcrackpolymerremovaltimeincreasesdrasticallywhenthesizwofthegreenbobyincreases,makingitdifficult,ifnotimpossible,toproducepartswiththickvrosssystemseithcatalyticdegradationofthepolymerhavebeendevelopedthathavetheporentialtoreducemanyofthepoblemsstatedabovethroughdepolymerizationandsublimationofrhemonomeratlowthiscatalyticdegradationapproach,theproblemsassociatedwiththethermalexpansionofthepolymer,capillaryforcesm,andparticlemigrationduetoliquidflowcanbe,becauseofthehighcostofthepolymersused,thisapproachhasfoundlimiteduse.Thedryingprocesshasamajorinfluenceongreenmicrostructureandproductionisacriticaloperation,whichhastobecontrolledtoavoidcrackingandisacoupledheat-andmass-transferproblemforwhichmathematicalrepresrntationshavebeenavailablefor desiredendinceramicpartproductionisfastdrying;however,fastdryingcausesstudieshaveshownthatdecreasingdryingratesresultsinincreasinggreendensities,andbinderadditivesstronglyaffectstressisinhibitedbystrengtheningthesolidsnetwork,increasingporesize,acdreducingcapollarydrying,transportofevaporatingdispersingmediacancausebinderandsmallparticlemigrationtothecanleadtoadditionalproblemsduringburnoutandproblemscanbeminimizedoravoededwhenthebindercontentislowtrthedispersingmediaissublimated.NovelCeramicProcessingMethod——DirectCasting陶瓷加工方式——直接成型Duringthepastdecade,anincreasingnumberofnovelnear-net-shape-formingtechniqueshavebeenpresentedtotheceramicclassofthesenewmethods,thedirect-castingmethods,usedsomeoftheinherentpropertiesofdensesuspensionstotransformafluidsuspensiontoastiffgeneralconceptistoretainthehomogeneousstateofehedenseslurryduringthegreen-bodyformationminimizingthedisturbancetotheslurryduringgelation,introductionoflargerheterogeneitiescanbeavoidedanddensitygradients physicalorchemicalprocessesresponsiblefortheformationofasolidgreenbodymayvary,butallmethodsrequireawell-dispersedsuspensionwith(very)highsolidsloadingofreasonablylowviscositytofacilitatethemold-filling,maximizingthesoledslosdingbytailoringtherangeandmagnitudeoftheinterparticlerepulsionandoptimazingtheparticle-sizedistributionbecomeveryimportantissues.Toensurehighreliabilityandreproducibilityofsinteredparts,thedenseslurriesmustbehomogeneouswithrespecttotheceramicparticlesandorganicprocessingofanytypeshouldbe,athoroughmixingormillingstepiscommontothepreparationofthestartingslurriesalsohavetobedeairedtoavoiddefectscausedbytrappedair(hardagglomerates,organicinclusions)arecommonlyremovedbyfiltrationbeforecasting.Theunderlyingmechanismsformostofthedirect-castingmethodsarerelatedtotheformationofeitherphysicalorchemicalbondsbetweeneithertheparticlesorsomespeciesinthedivisionbetweenphysicalandchemicalgelsissomewhatarbitrary,differingmainlyinthestrengthofthegreenbody;chemicalgelsaresubstantiallystrongerthanphysicalparticlegelsrelyontheformationofaphysicalbondbetweentheparticlesindensesuspensions.Thisismainlyachievedbymanipulatingtheinterparticleforcestobecomeattractive.Inelectrostaticallystabilizedslurries,thiscanbeachievedbychangingpHorincreasingsaltcontent,whereasstericallystabilizedsystemscanbeflocculatedbychangingthesolvencyoftheadsorbedpolymehighsolidsloading,particlegelscandevelopasufficientstrengthtosupporttheirownweightand,thusbehandledwithoutshape,becausenopermanentbondsbetweentheparticlesareformed,particlescanrearrangebecauseofthermalfluctuationsorgravity.Hence,aphysicalparticalgel,sometimesreferredtoasatransientgel,mayundergoaslowdensificationwithtime.Theformationofstronggelsiscommonlyaccompaniedbytheformationofpermanentchemicalbondsbetweeneithertheparticlesorsomespeciesintheexamplesaretheformationofapercolatingpolymernetworkbypolymerizingamonomerintheslurryandthegelationofdissolvedalsoincludemethodsthatuseaphasetransitionofthecontinuousmedia,.,freezingofwater,inthiscategory.Thedirect-castingmethodsareorganizedaccordingtofundamentalphysicalandchemicalprinciplesoftheirdispersingmechanismandgelling ofthedirect-castingmethodsusemorethanonephysicalorchemicalprinciplefordispersionandarecategorizedaccordingtothedominatingprinciples,and,wherenecessary,thespecificchemistryandphysicsarediscussedwitheach,wedescribeprocessesthatmanipulateinterparticlepotentialsandcreatephysicalgelsviaapercolatingnetworkof,wedescribepercolatingnetworksformedbyadditivesinthedispersingmediausingphysicalorchemicalprocesses.直接成型的方式是依照以下分散凝膠反映機(jī)制的大體物理和化學(xué)原理進(jìn)展的添加添加劑而形成的滲透網(wǎng)。AconcentratedAlOsuspensioncanbetransformedfromadispersed,fluidstate23intoaflocculated,rigidstatebyeitherchangingpHtowardtheisoelectricpoint(orpzc)orbyincreasingthesaltcontenttocompresstheelectricdoublechangescanbeinducedbyaddingacid,base,or,thereisalargeriskthatthesimultaneousmixingandgelationmayresultinlargeinhomogeneitiesinthedense betterapproachistouseareactionthatproducesthedesiredpHorsaltchangeinofsuchreactionsarethermallyactivateddecompositionofureawhichch