材料科学与工程基础

FundamentalsofmaterialsscienceandengineeringChapter1

IntroductiontoMaterialsScienceandEngineering

HaveYouEverWondered?Whatdomaterialsscientistsandengineersstudy?Howsheetsteelcanbeprocessedtoproduceahigh-strength，lightweight，energyabsorbing，malleable（可塑的，可锻的）materialusedinthemanufactureofcarchassis（底盘）?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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结实的；耐用的；坚固的

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手手指关关节FigureRepresentativestrengthsofvariouscategoriesofmaterials聚醚酮酮树脂脂聚乙烯烯环氧树树脂芳纶纤纤维聚酰亚亚胺聚酯纤纤维，涤纶纶2.FunctionalClassificationofMaterialsAerospace（航航空航航天））––lightmaterialsBiomedicalMaterialsElectronicMaterialsEnergyTechnologyandEnvironmentalTechnologyMagneticMaterialsPhotonicorOpticalMaterials(光光学材材料））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羟磷灰石Titaniumalloys,StainlesssteelsShape-memoryalloysPlastics,PZTAerospaceC-Ccomposites,SiO2,Amorphoussilicon,Ai-alloysSuperalloysMagneticMaterialsEnergyTechnology&EnvironmentalElectronicMaterialsFigureFunctionalclassificationofmaterials.Noticethatmetals,plastics,andceramicsoccurindifferentcategories.AlimitednumberofexamplesineachcategoryisprovidedClassificationofFunctionalMaterialsITO:In2O3-SnO2MR:magnetorheologyPZT:leadzicorniumtitanateYAG:yttriumaluminumgarnet(Y3Al5O12)磁流体铟-锡压电陶瓷(锆钛酸铅铅)(Y3Al5O12)(Y3Al5O12)3.ClassificationofMaterialsBasedonStructure(microstructure)Crystal（（晶体）-----thematerial’satomsarearrangedinaperiodicfashion.Amorphous（非晶体体）-----thematerial’’satomsdonothavealong-rangeorder.Singlecrystals（单单晶）-------somecrystallinematerialsmaybeintheformofonecrystal.Polycrystals（（多晶）---somecrystallinematerialsconsistofmanycrystalsorgrains.SEM5nmMSEXRD,TEMOptical19•transparency透明度:--氧化铝因其结构不同而透明、半透明、不透透明AdaptedfromFig.1.2,Callister7e.(Specimenpreparation,P.A.Lessing;photobyS.Tanner.)单晶(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（（尾部燃烧烧）sectionoperatesathightemperaturesandnickel-basedsuperalloysarerequired.Theoutsideshellexperienceslowtemperatures,andaluminumandcompositesaresatisfactory.(CourtesyofGEAircraftEngines.)FigureAvarietyofcomplexceramiccomponents,includingimpellers（叶叶轮）andblades,whichallowturbineenginestooperatemoreefficientlyathighertemperatures.(CourtesyofCertech,Inc.)FigurePolymersareusedinavarietyofelectronicdevices,includingthesecomputerdipswitches,wheremoistureresistanceandlowconductivityarerequired.(CourtesyofCTSCorporation.)FigureIntegratedcircuitsforcomputersandotherelectronicdevicesrelyontheuniqueelectricalbehaviorofsemiconductingmaterials.(CourtesyofRogersCorporation.)FigureTheX-wingforadvancedhelicoptersreliesonamaterialcomposedofacarbon-fiber-reinforcedpolymer.(CourtesyofSikorskyAircraftDivision——UnitedTechnologiesCorporation.)2.CorrosionoxygenorothergasesLiquidRadiation（辐射））,atomicoxygen,debris（碎石，废废石）2.Corrosionoxygenorothergases(1)Mostmetalsandpolymersreactwithoxygenorothergases,particularlyatelevatedtemperatures.(2)Metalsandceramicsmaydisintegrate.(3)Nonoxideceramicsandpolymersmayoxidize.liquidacid（（酸）alkali（（碱）salt（（盐）---leadingtoprematurefailureRadiation（辐射））,atomicoxygen,debris（（碎石，，废石）Inspaceapplications,wemayhavetoconsidertheeffectsofthepresenceofradiation,thepresenceofatomicoxygen,andtheimpactfromdebris.3.Fatigueloadandunloadthematerialthousandsoftimessmallcrackscracksgrowmaterialsfail4.Strain