FundamentalsofmaterialsscienceandengineeringChapter1

IntroductiontoMaterialsScienceandEngineering

HaveYouEverWondered?Whatdomaterialsscientistsandengineersstudy?Howsheetsteelcanbeprocessedtoproduceahigh-strength，lightweight，energyabsorbing，malleable（可塑的，可鍛的）materialusedinthemanufactureofcarchassis（底盤）?Canwemakeflexibleandlightweightelectroniccircuitsusingplastics?Whatisa“smartmaterial”?outlineWhatisMaterialsScienceandEngineering?ClassificationofMaterialsEnvironmentalandOtherEffectsMaterialsDesignandSelection1-1WhatisMaterialsScienceandEngineering?1.Definition

MaterialsScienceandEngineering(MSE)isaninterdisciplinaryfieldconcernedwithinventingnewmaterialsandimprovingpreviouslyknownmaterialsbydevelopingadeeperunderstandingofthemicrostructure-composition-synthesis-processingrelationship.▲ThetermComposition

Meansthechemicalmake-upofamaterial▲StructureAdescriptionofthearrangementofatoms,asseenatdifferentlevelsofdetail.▲SynthesisReferstohow

materialsaremadefromnaturallyoccuringorman-madechemicals.▲ProcessingMeanshowmaterialsareshapedintousefulcomponentstocausechangesinthepropertiesofdifferentmaterials.FigureApplicationofthetetrahedronofmaterialsscienceandengineeringtosheetsteelsforautomotivechassis.Notethatthemicrostructure-synthesisandprocessing-compositionareallinterconnectedandaffecttheperformance-to-costratioComposition;Strength;Weight;Energyabsorptionproperties;Malleability(formability)Strength-to-weightratioisthestrengthofamaterialdividedbyitsdensity;materialswithahighstrength-to-weightratioarestrongbutlightweight.FigureApplicationofthetetrahedronofmaterialsscienceandengineeringtosemiconductingpolymersformicroelectronics.

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結實的；耐用的；堅固的

SynthesisandprocessingHowcanpure,homogeneous,andfinepowdersofwell-definedstoichiometrybemade?Howdowemakelonglengthsofwires?FigureApplicationofthetetrahedronofmaterialsscienceandengineeringtoceramicsuperconductors.Notethatthemicrostructure-synthesisandprocessing-compositionareallinterconnectedandaffecttheperformance-to-costratio

Whatisthecurrentcarryingcapacity?Whatisthecastofcoolingandfabrication?MicrostructureWhatfeaturesofthestructurelimitthecurrentcarryingcapacity?Whatisthetextureofthematerial?CompositionYBa2Cu3O7-xYBa2Ca3Cu4O11YSr2Ca2Cu3O10PerformanceCastTetrahedronofMSE2.MaterialsScienceTheemphasisisontheunderlyingrelationshipsbetweenthesynthesisandprocessing,structure,andpropertiesofmaterials.3.MaterialsEngineeringThefocusisonhowtotranslateortransformmaterialsintoausefuldeviceorstructure.

ApplicationOFTetrahedron:asampleproduct––ceramicsuperconductorsinventedin1986(1)DISCOVERY(2)LIMITATION(3)IMPROVEMENT(4)SOLUTION(5)BRITTLE(6)SOLUTION1-2ClassificationOfMaterialsAccordingtodifferentpropertiesFunctionalClassificationofMaterialsClassificationofMaterialsBasedonStructure(microstructure)ClassificationPropertiesApplicationMetalsgoodelectricalandthermalconductivityautomobileengine(steels,aluminum,relativelyhighstrength,stiffness,aircraft,electricalmagnesium)ductivity,formabilityconductorwireCeramicshighmeltingpoint,strength,hardnesshousecomputerchip(Si,SiO2,Al2O3,capacitors,electricalinsulation,MgO,SiC,Si3N4)sanitaryware,abrasivePolymerselectricalresistivity,thermalinsulation,foodpackaginglowstrengthliquidcrystaldisplays(LCD)Semiconductor(Silicon,GaAs)convertelectricalsignalstolighttransistors,diodeslasers,etcintegratedcircuitsCompositeshighhardness,goodshockresistance,sportsequipment,fiberglasshighstrength-to-weightratioaircraft,matrix1.AccordingtodifferentpropertiesBiomaterials生物功功能性性(biofunctionability)和生物物相容容性(biocompatibility)metallic,ceramic,polymermaterialsfingerjointteeth手手指關關節FigureRepresentativestrengthsofvariouscategoriesofmaterials聚醚酮酮樹脂脂聚乙烯烯環氧樹樹脂芳綸纖纖維聚酰亞亞胺聚酯纖纖維，滌綸綸2.FunctionalClassificationofMaterialsAerospace（航航空航航天））––lightmaterialsBiomedicalMaterialsElectronicMaterialsEnergyTechnologyandEnvironmentalTechnologyMagneticMaterialsPhotonicorOpticalMaterials(光光學材材料））SmartMaterialsStructuralMaterialsStructuralSteelAluminumalloysConcreteFiberglassPlastic,WoodSmartmaterialsPZTShape-memoryalloysMRfluidPolymergelsOpticalMaterialsSiO2,GaAsGlasses,Al2O3YAG,ITOFe,Fe-Si,NiZnAndMnZnferrites;Co-Pt-Ta-Crg-Fe2O3UO2,Ni-Cd,ZrO2,LiCoC2,AmorphousSi:HSi,GaAs,Ge,BaTiO3,PZT,YBa2Cu3O7,Al,Cu,W,ConductingpolymerBiomedicalHydroxyapatite羥磷灰石Titaniumalloys,StainlesssteelsShape-memoryalloysPlastics,PZTAerospaceC-Ccomposites,SiO2,Amorphoussilicon,Ai-alloysSuperalloysMagneticMaterialsEnergyTechnology&EnvironmentalElectronicMaterialsFigureFunctionalclassificationofmaterials.Noticethatmetals,plastics,andceramicsoccurindifferentcategories.AlimitednumberofexamplesineachcategoryisprovidedClassificationofFunctionalMaterialsITO:In2O3-SnO2MR:magnetorheologyPZT:leadzicorniumtitanateYAG:yttriumaluminumgarnet(Y3Al5O12)磁流體銦-錫壓電陶瓷(鋯鈦酸鉛鉛)(Y3Al5O12)(Y3Al5O12)3.ClassificationofMaterialsBasedonStructure(microstructure)Crystal（（晶體）-----thematerial’satomsarearrangedinaperiodicfashion.Amorphous（非晶體體）-----thematerial’’satomsdonothavealong-rangeorder.Singlecrystals（單單晶）-------somecrystallinematerialsmaybeintheformofonecrystal.Polycrystals（（多晶）---somecrystallinematerialsconsistofmanycrystalsorgrains.SEM5nmMSEXRD,TEMOptical19?transparency透明度:--氧化鋁因其結構不同而透明、半透明、不透透明AdaptedfromFig.1.2,Callister7e.(Specimenpreparation,P.A.Lessing;photobyS.Tanner.)單晶(transparent)多晶：低孔隙度（translucent;semitransparent）

多晶：高孔隙度（opaque）1-3EnvironmentalandOtherEffectsTemperatureCorrosionFatigueStrainRate1.TemperatureHightemperature-----changethestructureofceramicsandcausepolymerstomeltorcharLowtemperature----causeametalorpolymerstofailinabrittlemanner,eventhoughtheappliedloadsarelow.FigureIncreasingtemperaturenormallyreducesthestrengthofamaterial.Polymersaresuitableonlyatlowtemperatures.Somecomposites,specialalloys,andceramics,haveexcellentpropertiesathightemperaturesTEMPERATUREFigureAsectionthroughajetengine.Theforwardcompressionsectionoperatesatlowtomediumtemperatures,andtitaniumpartsareoftenused.Therearcombustion（（尾部燃燒燒）sectionoperatesathightemperaturesandnickel-basedsuperalloysarerequired.Theoutsideshellexperienceslowtemperatures,andaluminumandcompositesaresatisfactory.(CourtesyofGEAircraftEngines.)FigureAvarietyofcomplexceramiccomponents,includingimpellers（葉葉輪）andblades,whichallowturbineenginestooperatemoreefficientlyathighertemperatures.(CourtesyofCertech,Inc.)FigurePolymersareusedinavarietyofelectronicdevices,includingthesecomputerdipswitches,wheremoistureresistanceandlowconductivityarerequired.(CourtesyofCTSCorporation.)FigureIntegratedcircuitsforcomputersandotherelectronicdevicesrelyontheuniqueelectricalbehaviorofsemiconductingmaterials.(CourtesyofRogersCorporation.)FigureTheX-wingforadvancedhelicoptersreliesonamaterialcomposedofacarbon-fiber-reinforcedpolymer.(CourtesyofSikorskyAircraftDivision——UnitedTechnologiesCorporation.)2.CorrosionoxygenorothergasesLiquidRadiation（輻射））,atomicoxygen,debris（碎石，廢廢石）2.Corrosionoxygenorothergases(1)Mostmetalsandpolymersreactwithoxygenorothergases,particularlyatelevatedtemperatures.(2)Metalsandceramicsmaydisintegrate.(3)Nonoxideceramicsandpolymersmayoxidize.liquidacid（（酸）alkali（（堿）salt（（鹽）---leadingtoprematurefailureRadiation（輻射））,atomicoxygen,debris（（碎石，，廢石）Inspaceapplications,wemayhavetoconsidertheeffectsofthepresenceofradiation,thepresenceofatomicoxygen,andtheimpactfromdebris.3.Fatigueloadandunloadthematerialthousandsoftimessmallcrackscracksgrowmaterialsfail4.Strain