陶瓷加工方式专业英语原文

3仓促之作，如有纰漏，请自行修改！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.从制备悬浊浮液开头的。陶瓷颗粒〔粉末，晶须〕和水或熔化的聚合物，分散剂和可能需要的添加剂如：黏合剂，塑化剂，去泡剂相混合来取得分散良好，没有团聚的浆体。Withthegrowingawarenessofthedetrimentaleffectsofdifferenttypesofheterogeneitiesonthematerialspropertiesofmainlystructuralceramics,aconceptcalledcolloidalprocessinghasbeenintroducedasausefulapproachforflawofcolloidalprocessingincluderemovaloflarge,hardagglomeratesinthestartingpowderthroughsedimentationorfiltrationofwell-dispersedsuspensionsandthedevelopmentofdesigned,orderedmixturesofseveralcomponentsthroughthemanipulationoftheinterparticleconceptsapplytomostconventionalprocessingmethods,andtheyalsocanbeusedforthedevelopmentofnewprocessingtechniques.随着对不同类型的非均质性的主要构造陶瓷的材料性能不利影响的日趋生疏能够用来进展为处置技术。Drypressingandcoldisostaticpressing(CIPing)areprobablythemostimportantformingtechniquesforindustrialproductionofceramicbodiesareformedbypressinggranulesinafree-flowinggranulesareformedfromasuspensionusingagranulationtechnique,.,spraydryingorfreeze isanestablishedformingtechniquethathasexistedfordecadesandhasbeenusedformanyapplications,rangingfromdinnerwaretoinsulatorsandspark,therearedevelopmentsinthefieldinvolvinghigh-pressureCIPingandcyclicCIPingthatcanproducegreenbodiesofhigher majoradvantageofdrypressingisproductivity;modempressescanproduceasmanyas20partspermakespressingthemethodofchoiceformostindustrialceramicoperationsdespitetheproblemsassociatedwithdensitygradients,inhomogeneousmicrostructures,andtheneedtomachinecmplex-shapedobjects.〔CIPing〕方式能够生产高密度的陶瓷生坯。干压的主要优势是生产率;调制解调器压力机每分钟能够生产多达20件。虽然存在与密度梯度、非均匀微构造，和机械加工简单外形物体的相关问题，压制方式仍是成了大部份工业陶瓷经营商的首选。Allthedrain-castingtechniques.,slipcasting,pressurecasting,andcentrifugalcastinginvolveasolid-liquidseparationprocesstoformadensegreenliquidflowisdrivenbyeitheranexternalpressuregradient(slipcasting,pressurecasting)orabodyforceinacentrifugalforcefield(centrifugalcasting).Slipcastingisalow-pressurefiltrationmethodwherecapillarysuctionprovidesthedrivingforce(ontheorderof~forliquidremovalandformationofacastlayeratamoldcastingisgenerallyaslowprocess,becausethecastingratedecreasesparabolicallywiththicknessofthecastcastingwhichisanestablishedformingtechniqueinfabricationoftraditionalclay-basesceramicmaterials,suchaspotteryandsanitaryporcelain---andpressurefiltrationaremodificationsofslipcastingthathavebeendevelopedtoacceleratetheconsolidationstageandtoobtainahighergreenthesemethods,anexternalpressure(<4MPa)substantiallyhigherthanthecapillarysuctionpressureisappliedtotheceramicsuspension.程，会形成致密的坯体。液体的流淌是受一个外部压力梯度〔注浆，压力成型，或离心力场〔离心成型〕的驱动。注浆成型时一个低压过滤的进程。在那个进程中，毛细管的吸力把成型率随着成型厚度呈抛物线下降。压力注浆成型是成立在传统的粘土陶瓷材料的制造技良，并取得较高的绿色密度。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胶反映机制的大体物理和化学原理进展的添加添加剂而形成的渗透网。AconcentratedAlOsuspensioncanbetransformedfromadispersed,fluidstate23intoaflocculated,rigidstatebyeitherchangingpHtowardtheisoelectricpoint(orpzc)orbyincreasingthesaltcontenttocompresstheelectricdoublechangescanbeinducedbyaddingacid,base,or,thereisalargeriskthatthesimultaneousmixingandgelationmayresultinlargeinhomogeneitiesinthedense betterapproachistouseareactionthatproducesthedesiredpHorsaltchangeinofsuchreactionsarethermallyactivateddecompositionofureawhichch