陶瓷ceramics材料概論

IntroductiontomaterialsCeramicsforfinalexaminationEditors:卜嬌嬌蘇潔瓊孟夢馬世行耿玉華余煒CeramicsCeramicscanbedefinedasinorganic,nonmetallicmaterials.Theyaretypicallycrystallineinnatureandarecompoundsformedbetweenmetallicandnonmetallicelements.Ceramics

TraditionalceramicsAdvancedceramicsIntroductionTraditionalceramicsTraditionalceramicsarederivedandprocessedfromclayornonclayminerals.Theyarechemicallycomplex,buttheyarecommon,inexpensive,andeasytomanufactureCharacteristics

:fragilenotconsideredforuseasstructuralorload-bearingmaterialsheavyAdvancedceramicsThegreatestdemandinland,sea,air,andspaceindustriesmakesAdvancedceramicsappear.Someexamplesofadvancedceramicsincludeoxideceramicssuchasalumina,beryllia,andzirconiaandnonoxideceramicswhichcanberepresentedbycarbidesandnitridessuchasboroncarbide,andsiliconnitride.ClaysRefractories(耐火材料)GlassesCementAbrasivesTraditionalCeramicsMaterialsTaxonomyofTraditionalCeramicsMaterialsBasedonApplicationsAdvanced(new)CeramicsMaterialsOxidesNitridesCarbidesTaxonomyofAdvanced(new)CeramicsMaterialsBasedonApplicationsStructureofCeramicsLoosedefinition:Crystallinesolidscomposedofmetallicandnonmetallicmaterials.

ReasonConsistingprimarilyofformsofsilicon,aluminum(鋁)andoxygenWhyceramiccanbeproducedatlesscostthanmetal?Whatsetsceramicsapartistheirsetofpropertiescommontonearlyallforms:

（1）extremehardness,

(2)heatresistance

(3 )corrosionresistance

(4）lowelectricalandthermal

conductivity

（5）lowductility,orbrittleness.CrystalofStructures

●Mainmaterialofceramicsissilicates.ThebasicunitofthesilicatestructureisSiO4tetrahedron.●Whenclayisheatedtoover1100℃inakiln,thewaterisremovedandthelayeredsheetsbondorlockintoarigidstructure.Thesolidstructureiscalledaceramic.MicrostructuresofStructures

3.Theprocessingofceramics

3.TheprocessingofceramicsTheAdvancedCeramicProcessing

TraditionalCeramicProcessing3.1AdvancedCeramicProcessingpowderpressinguniaxialisostatichotpressingthemultistagefabricationprocess

acoldstep

ahotstep3.2TraditionalCeramicProcessing

rawmaterialsformingtechniquesdryingandfireingtestingpackingstorige3.2traditionalceramicprocessingrawmaterialsClassificationofrawmaterials

：ceramicmanufactureandbasicmaterial

plasticrawmaterial

Ceramicrawmaterial

non-plasticrawmaterialClay

Silica

3.2Traditionalceramicprocessing

Formingtechniques

hydroplasticformingtwocommonshapingtechniques

slipcasting

drying

dryingandfiring

firingtesting

packingstorigePropertiesofCeramicsMechanicalPropertiesPhysicalPropertiesChemicalPropertiesFabricabilityOtherPropertiesWearresistanceThermalshockresistanceMechanicalProperties

Tensilestrength:Itisoftensubstitutedforthetensilemodulusofelasticity(拉伸彈性模量)Yieldstrength:CeramicsdonothaveayieldstrengthHardness:CeramicshavethehardesthardnessoftheengineeringmaterialsStiffness:CeramicscomeoutasourstiffestengineeringmaterialsBrittleness:TheirgreatestweaknessisbrittlenessCompressivestrength:EngineeringceramicshaveanexcellentcompressivestrengthPhysicalproperties

Density:0.1-0.6comparedto0.06-0.8ofmetalsMeltingpoints:TheyareamongthehighestofallengineeringmaterialsThermalandelectricalconductivity:MostceramicshavelowthermalconductivityandareelectricalinsulatorsAtenttion:temperatureWaterabsorption:Itcanbeafactorwithceramicsthatcontainporosity.AbsorbedmoisturecanlowerelectricalinsulatingpropertiesofporousceramicsChemicalProperties

Crystalline:Mostofceramicsarecrystalline,but,glassesareamorphous,notcrystallineatallChemicalresistance:Ceramicshaveanexcellentchamicalresistance(suchascorrosionresistance)Composition:Ingeneral,wedonotstatethechemicalcompositionofceramicsFabricabilityANDOtherProperties

Fabrication:CeramicscannotbemeltedandcasttoshapeslikemetalsCostly:Mostceramicsrequireexpensiveprocessingtobringthemtomanymachineparts,andthetechnologyofsol-gel(溶膠凝膠)doesnotexistonacommercialbasisin2000,butitmaycome.Areyou???WearresistanceThermalShockresistanceApplicationsofCeramicMedical

ConstructionIndustryRefractoriesElectricalApplicationEnvironmentalandSpaceApplicationUsesintheConstructionIndustry

1)Ceramicmaterialsplayanimportantroleinconstructionindustry(2)Productssuchasfloor,wallandroofing-tile,brickarethebuildingblocksintheworldofconstructionCeramictileClaybrickUseinRefractoriesCeramiccrucibleTheceramicisoneoftherefractoriesRefractoryceramiccanwithstandvolatileandhigh-temperature.CeramicfiberMedical

Surgeonsareusingbio-ceramicmaterialsforrepairandreplacementofhumanhips,knees,andotherbodyparts.Dentistsareusingceramicsfortooth

ElectricalApplicationsCeramicisimportantinelectronicindustryCeramichaveawiderangeofelectricalpropertiesincludinginsulating,semi-conducting,superconducting,piezoelectricandmagnetic.

EnvironmentalandspaceapplicationsThecellularceramicshelpcatalyticconvertnoxioushydr