陶瓷加工方式專業(yè)英語原文

3倉促之作，如有紕漏，請自行修改！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，去泡劑相混合來取得分散良好，沒有團聚的漿體。Withthegrowingawarenessofthedetrimentaleffectsofdifferenttypesofheterogeneitiesonthematerialspropertiesofmainlystructuralceramics,aconceptcalledcolloidalprocessinghasbeenintroducedasausefulapproachforflawofcolloidalprocessingincluderemovaloflarge,hardagglomeratesinthestartingpowderthroughsedimentationorfiltrationofwell-dispersedsuspensionsandthedevelopmentofdesigned,orderedmixturesofseveralcomponentsthroughthemanipulationoftheinterparticleconceptsapplytomostconventionalprocessingmethods,andtheyalsocanbeusedforthedevelopmentofnewprocessingtechniques.隨著對不同類型的非均質性的主要構造陶瓷的材料性能不利影響的日趨生疏能夠用來進展為處置技術。Drypressingandcoldisostaticpressing(CIPing)areprobablythemostimportantformingtechniquesforindustrialproductionofceramicbodiesareformedbypressinggranulesinafree-flowinggranulesareformedfromasuspensionusingagranulationtechnique,.,spraydryingorfreeze isanestablishedformingtechniquethathasexistedfordecadesandhasbeenusedformanyapplications,rangingfromdinnerwaretoinsulatorsandspark,therearedevelopmentsinthefieldinvolvinghigh-pressureCIPingandcyclicCIPingthatcanproducegreenbodiesofhigher majoradvantageofdrypressingisproductivity;modempressescanproduceasmanyas20partspermakespressingthemethodofchoiceformostindustrialceramicoperationsdespitetheproblemsassociatedwithdensitygradients,inhomogeneousmicrostructures,andtheneedtomachinecmplex-shapedobjects.〔CIPing〕方式能夠生產高密度的陶瓷生坯。干壓的主要優(yōu)勢是生產率;調制解調器壓力機每分鐘能夠生產多達20件。雖然存在與密度梯度、非均勻微構造，和機械加工簡單外形物體的相關問題，壓制方式仍是成了大部份工業(yè)陶瓷經(jīng)營商的首選。Allthedrain-castingtechniques.,slipcasting,pressurecasting,andcentrifugalcastinginvolveasolid-liquidseparationprocesstoformadensegreenliquidflowisdrivenbyeitheranexternalpressuregradient(slipcasting,pressurecasting)orabodyforceinacentrifugalforcefield(centrifugalcasting).Slipcastingisalow-pressurefiltrationmethodwherecapillarysuctionprovidesthedrivingforce(ontheorderof~forliquidremovalandformationofacastlayeratamoldcastingisgenerallyaslowprocess,becausethecastingratedecreasesparabolicallywiththicknessofthecastcastingwhichisanestablishedformingtechniqueinfabricationoftraditionalclay-basesceramicmaterials,suchaspotteryandsanitaryporcelain---andpressurefiltrationaremodificationsofslipcastingthathavebeendevelopedtoacceleratetheconsolidationstageandtoobtainahighergreenthesemethods,anexternalpressure(<4MPa)substantiallyhigherthanthecapillarysuctionpressureisappliedtotheceramicsuspension.程，會形成致密的坯體。液體的流淌是受一個外部壓力梯度〔注漿，壓力成型，或離心力場〔離心成型〕的驅動。注漿成型時一個低壓過濾的進程。在那個進程中，毛細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制的大體物理和化學原理進展的添加添加劑而形成的滲透網(wǎng)。AconcentratedAlOsuspensioncanbetransformedfromadispersed,fluidstate23intoaflocculated,rigidstatebyeitherchangingpHtowardtheisoelectricpoint(orpzc)orbyincreasingthesaltcontenttocompresstheelectricdoublechangescanbeinducedbyaddingacid,base,or,thereisalargeriskthatthesimultaneousmixingandgelationmayresultinlargeinhomogeneitiesinthedense betterapproachistouseareactionthatproducesthedesiredpHorsaltchangeinofsuchreactionsarethermallyactivateddecompositionofureawhichch