清华相变晶体学2014part1a

相变晶体学张文征Lecture1,partaIntroduction,generalviewDec.4,2014材料科学的四要素性能及服役行为/成本常用材料科学四面体MSEtetrahedron工艺及合成成分或组成组织或微结构四要素中是否有一个材料科学的核心元素？MaterialsScience（MS）微观组织-结构的知识是材料科学的核心任何性能的改变都可以从组织-微结构上找到原因MS=linksbetweendifferentelements?propertiesperformancecompositionsprocessesmicrostructurepropertiesperformancecompositionsprocessesmicrostructureMS=linksFace-center-triangle我的定义MSEtetrahedron常用四面体定义EngineBlock1meterMicrostructure-Grains1–10mmProperties•Highcyclefatigue•DuctilityMicrostructure-Phases100–500micronsProperties•Yieldstrength•Ultimatetensilestrength•Highcyclefatigue•Lowcyclefatigue•ThermalGrowth•DuctilityAtoms2-100AngstromsProperties•ThermalGrowth•Young’smodulusMicrostructure-Phases1-100nanometersProperties•Yieldstrength•Ultimatetensilestrength•Lowcyclefatigue•Ductility组织结构显微组织(微结构)包括什么？FromMeiLi,Ford支配性能的复相材料的微结构：组成相性质、相分布、尺寸、数量、形状、取向、界面、缺陷、成分分布，键等PrecipitatemicrostructureinanAlalloyusedforwinginaBoeing767MicrostructuresinmanymaterialsaredevelopedfromphasetransformationsTransformationproductsoftenexhibitreproduciblecrystallographicmorphologyMorphologyisaanessentialelementofmicrostructureLessmatureduetotoolsavailablemuchlaterthanopticalmicroscopesLesseasytogaininformationbecauseskillsdemandedintheresearchLessattentioncomparedtothermodynamicandkineticsDefinitionUsingTEMandEBSD/SEM,theaboveinformationcanbemeasured,anddataisaccumulated(adatabaseisbeingbuilt,anSRTprogram)“晶体学通过相变时晶体结构的变化过程，揭示相变的物理本质，因此相变晶体学是相变机制的核心部分。”摘自《马氏体相变与马氏体》—徐祖耀，相变领域国内外知名学者Crystallographyofphasetransformations(CPT)isaboutdescriptionandunderstandingofCrystallographicorientationrelationship（位向关系）betweenphasesandCrystallographicmorphologyofproductphaseincrystalbasesDetailsCrystallographicmorphologyiscloselyrelatedtointerphaseinterfaces.ThescopeofCPTincludesQuantitativedescription,characterization,andunderstanding:Crystallographicorientationofinterfacesorshapeofparticles--Whyaresomeparticularinterfacespreferred?--Howdoescrystallographicmorphologyevolvefromnucleationandgrowth?--Whatandwhyistherelationshipbetweeninterfacialstructuresandsegregationofelements?–changeofmorphologywithalloyingDefectsandarrangementofatomsintheinterfaces--HowandwhydoesexistingdislocationsaffecttheORandvariantselectionsStrainfieldaroundtheproductphase--Howtheappliedfiledaffectthevariantselection?《材料相变》徐祖耀主编，高等教育出版社,2013Whydowecare?Astudyofmorphologyisnotjustforcuriosityaboutthefascinatingfeature,butaimsatagoalforcontrolanddesignofmicrostructureandpropertiesAcorrectdescriptionoftheinterfacialstructuresisessentialforunderstandofinterfaces,e.g.theenergycharacteristicofpreferredinterfacesthecompositionanddynamicsinterfaces(transformationmechanism,interfaceengineering)theroleofinterfacesindislocationmotionindeformationandrecoverythepossiblelong-rangestrainfieldanditsinteractionwithotherfiled,affectingvariantselection&texturedevelopmentOptimizingpropertiesbymanipulatinginterfacesWhydowecareaboutinterfaces？Understandingofinterfaceshelpstomodeling,controllinginterfaces,&inturnunderstanding,modeling,controllingmicrostructuredevelopedinprocess,andeventuallyunderstanding,modeling,controllingpropertiesofvariousmultiphasecrystallinematerialsInterphaseinterfacesphasetransformationMaterialsMaterialsUrsulaR.Kattneretal.MetallurgyDivision,MML,NIST,March15,2012Whatareinterfacestoexist?MGI=MaterialsGenomeInitiativeWhydowecareaboutinterfaces？ApplicabletoFe,Al,Ti,Cu,MgalloysLatticefitistooltodeterminethehabitplaneOutlineIntroductionCrystallographyofPrecipitationMatrixExpressionsofPhaseTransformation(O-Lattice)ExamplesofapplicationsSummary侧重分析方法，和基本概念OutlinexThetheoryoftransformationsinmetalsandalloys:anadvancedtextbookinphysicalmetallurgy/J.W.Christian.Edition3rded.ImprintOxford,NewYork,PergamonPress,2002WorkedexamplesintheGeometryofCrystals,Secondedition/H.K.D.H.Bhadeshia(e-bookfreetodownload,2001)IntroductiontotheCrystallographyofMartensiticTransformations/WaymanCM.NewYork:MacMillan,1964Crystaldefectsandcrystallineinterfaces,(Berlin:Springer,1970).Crystallattices,interfaces,matrices,(Geneva:Bollmann,1982)/W.Bollmann相变原理(第三版，北京：科学出版社，2000)马氏体相变与马氏体(北京:科学出版社,1999)/徐祖耀著OntheCrystallographyofPrecipitation,Prog.Mater.Sci.vol.50,181-292.Zhang,W.-Z.andWeatherly,G.C.,(2005)材料相变，第四章相变晶体学，高教出版社，2013，徐祖耀主编ReferencesTheselectedworksofJohnW.Cahn/TMS,1998LecturesontheTheoryofPhaseTransformations,/ed.H.I.AaronsonMechanismsofDiffusionalPhaseTransformationsinMetalsandAlloys/HubertI.Aaronson,MasatoEnomoto,JongK.Lee,2010Phaseequilibria,phasediagrams,andphasetransformations:theirthermodynamicbasis/MatsHillert.NewYork:CambridgeUniversityPress,1998DefinitionandbasicconceptsWhydowestudycrystallographyofphasetransformations?ReferencesGeneralreviewIntroductionGivenfull5Dfreedom,whatinterfacesarepreferred?Manyinterfacesarereproducible,withtheirgeometryatlimitedlocationsinthe5Dspace5D?Fivedegrees(5D)offreedomtodefineinterfacegeometry:3fororientationrelationship2forinterfaceorientationWhatdeterminescrystallographicmorphology?Anold(200y)puzzleinmaterialsscien