材料導(dǎo)論詞匯

7/11Chapter1IntroductionReadthetextbook（P3）andanswerthefollowingquestion：Whatisthephenomenon?Andwhy?Youshouldbeabletodothefollowing:1.Listsixdifferentpropertyclassificationsofmaterialsthatdeterminetheirapplicability.2.Citethefourcomponentsthatareinvolvedinthedesign,production,andutilizationofmaterials,andbrieflydescribetheinterrelationshipsbetweenthesecomponents.3.Citethreecriteriathatareimportantinthematerialsselectionprocess.4.(a)Listthethreeprimaryclassificationsofsolidmaterials,andthencitethedistinctivechemicalfeatureofeach.(b)Notetheotherthreetypesofmaterialsand,foreach,itsdistinctivefeature(s).Chapter2InteratomicBonding1Makesureyouunderstandconcepts:“Covalentbond共價(jià)鍵Aprimaryinteratomicbondthatisformedbythesharingofelectronsbetweenneighboringatoms.“Dipole(electric)偶極Apairofequalyetoppositeelectricalchargesthatareseparatedbyasmalldistance.“Hydrogenbond氫鍵Astrongsecondaryinteratomicbondthatexistsbetweenaboundhydrogenatom(itsunscreenedproton)andthelectronsofadjacentatoms.“Ionicbond離子鍵Acoulombicinteratomicbondthatexistsbetweentwodjacentandoppositelychargedions.“Metallicbond金屬鍵Aprimaryinteratomicbondinvolvingthenondirectionalsharingofnonlocalizedvalenceelectrons(‘‘seaofelectrons’’)thataremutuallysharedbyalltheatomsinthemetallicsolid.“Polarmolecule極性分子Amoleculeinwhichthereexistsapermanentelectricdipolemomentbyvirtueoftheasymmetricaldistributionofpositivelyandnegativelychargedregions.“Primarybonding主價(jià)鍵Interatomicbondsthatarerelativelystrongandforwhichbondingenergiesarerelativelylarge.Primarybondingtypesareionic,covalent,andmetallic.“Secondarybonding次價(jià)鍵Interatomicandintermolecularbondsthatarerelativelyweakandforwhichbondingenergiesarerelativelysmall.Normallyatomicormoleculardipolesareinvolved.SecondarybondingtypesarevanderWaalsandhydrogen.“VanderWaalsbond范德華鍵Asecondaryinteratomicbondbetweenadjacentmoleculardipoles,whichmaybepermanentorinduced.“Valenceelectron價(jià)電子Theelectronsintheoutermostoccupiedelectronshell,whichparticipateininteratomicbonding.2youshouldbeabletodothefollowing:(1)Brieflydescribeformationandcharacteristicsofionic,covalent,metallic,hydrogen,andvanderWaalsbonds.(2)Notewhatmaterialsexhibiteachofthesebondingtypes.Chapter3StructureofSolids1．Makesureyouunderstandlanguageandconcepts:Allotropy同素異形現(xiàn)象，同素異構(gòu)現(xiàn)象Thepossibilityofexistenceoftwoormoredifferentcrystalstructuresforasubstance(generallyanelementalsolid).Amorphous無定形的，非晶態(tài)的Havinganoncrystallinestructure.Anisotropy各向異性Exhibitingdifferentvaluesofapropertyindifferentcrystallographicdirections.Atomicpackingfactor(APF)原子密堆因素Body-centeredcubic(BCC)體心立方Coordinationnumber配位數(shù)Thenumberofatomicorionicnearestneighbors.Crystalstructure晶體結(jié)構(gòu)Forcrystallinematerials,themannerinwhichatomsorionsarearrayedinspace.Itisdefinedintermsoftheunitcellgeometryandtheatompositionswithintheunitcell.Crystalline晶體的Thestateofasolidmaterialcharacterizedbyaperiodicandrepeatingthree-dimensionalarrayofatoms,ions,ormolecules.Face-centeredcubic(FCC)面心立方Grain晶粒Anindividualcrystalinapolycrystallinemetalorceramic.Grainboundary晶界Theinterfaceseparatingtwoadjoininggrainshavingdifferentcrystallographicorientations.Hexagonalclose-packed(HCP)密排六方Isotropic各向同性的Havingidenticalvaluesofapropertyinallcrystallographicdirections.Latticeparameter晶格參數(shù)Thecombinationofunitcelledgelengthsandinteraxialanglesthatdefinestheunitcellgeometry.Non-crystalline非晶的Thesolidstatewhereinthereisnolong-rangeatomicorder.Sometimesthetermsamorphous,glassy,andvitreousareusedsynonymously.Polycrystalline多晶的Referringtocrystallinematerialsthatarecomposedofmorethanonecrystalorgrain.Polymorphism多晶型現(xiàn)象，同質(zhì)異構(gòu)現(xiàn)象Theabilityofasolidmaterialtoexistinmorethanoneformorcrystalstructure.Singlecrystal單晶Acrystallinesolidforwhichtheperiodicandrepeatedatomicpatternextendsthroughoutitsentiretywithoutinterruption.Unitcell晶胞，單胞Thebasicstructuralunitofacrystalstructure.Itisgenerallydefinedintermsofatom(orion)positionswithinaparallelepipedvolume.2.Youshouldbeabletodothefollowing1.Describethedifferenceinatomic/molecularstructurebetweencrystallineandnoncrystallinematerials.2.Drawunitcellsforface-centeredcubic,body-centeredcubic,andhexagonalclose-packedcrystalstructures.3.Computethedensitiesformetalshavingface-centeredcubicandbody-centeredcubiccrystalstructuresgiventheirunitcelldimensions.4.Distinguishbetweensinglecrystalsandpolycrystallinematerials.5.Defineisotropyandanisotropywithrespecttomaterialproperties.Chapter4ImperfectionsinsolidsMakesureyouunderstandlanguageandconceptsAlloy合金Ametallicsubstancethatiscomposedoftwoormoreelements.Atompercent原子百分?jǐn)?shù)Concentrationspecificationonthebasisofthenumberofmoles(oratoms)ofaparticularelementrelativetothetotalnumberofmoles(oratoms)ofallelementswithinanalloy.Atomicvibration原子振動(dòng)Thevibrationofanatomaboutitsnormalpositioninasubstance.Boltzmann‘sconstant波爾茲曼常數(shù)Burgersvector柏氏矢量Avectorthatdenotesthemagnitudeanddirectionoflatticedistortionassociatedwithadislocation.Composition成分Therelativecontentofaparticularelementorconstituent(i)withinanalloy,usuallyexpressedinweightpercentoratompercent.Defectstructure缺陷構(gòu)造Relatingtothekindsandconcentrationsofvacanciesandinterstitialsinaceramiccompound.Dislocationline位錯(cuò)線Thelinethatextendsalongtheendoftheextrahalf-planeofatomsforanedgedislocation,andalongthecenterofthespiralofascrewdislocation.Edgedislocation刃位錯(cuò)Alinearcrystallinedefectassociatedwiththelatticedistortionproducedinthevicinityoftheendofanextrahalfplaneofatomswithinacrystal.TheBurgersvectorisperpendiculartothedislocationline.Electroneutrality電中性Thestateofhavingexactlythesamenumbersofpositiveandnegativeelectricalcharges(ionicandelectronic),thatis,ofbeingelectricallyneutral.Frenkeldefect弗蘭克缺陷Inanionicsolid,acation–vacancyandcation–interstitialpair.Grainsize晶粒尺寸Theaveragegraindiameterasdeterminedfromarandomcrosssection.Imperfection缺陷，非理想性Adeviationfromperfection;normallyappliedtocrystallinematerialswhereinthereisadeviationfromatomic/molecularorderand/orcontinuity.Interstitialsolidsolution間隙式固溶體Asolidsolutionwhereinrelativelysmallsoluteatomsoccupyinterstitialpositionsbetweenthesolventorhostatoms.Microscopy顯微鏡法Theinvestigationofmicrostructuralelementsusingsometypeofmicroscope.Microstructure顯微結(jié)構(gòu)，微觀結(jié)構(gòu)Thestructuralfeaturesofanalloy(e.g.,grainandphasestructure)thataresubjecttoobservationunderamicroscope.Mixeddislocation混合位錯(cuò)Adislocationthathasbothedgeandscrewcomponents.Photomicrograph顯微照片Thephotographmadewithamicroscope,whichrecordsamicrostructuralimage.Pointdefect點(diǎn)缺陷Acrystallinedefectassociatedwithoneor,atmost,severalatomicsites.Scanningelectronmicroscope(SEM)掃描電子顯微鏡Scanningprobemicroscope(SPM)掃描探針顯微鏡Schottkydefect肖脫基缺陷Inanionicsolid,adefectconsistingofacation–vacancyandanion–vacancypair.Screwdislocation螺旋位錯(cuò)Alinearcrystallinedefectassociatedwiththelatticedistortioncreatedwhennormallyparallelplanesarejoinedtogethertoformahelicalramp.TheBurgersvectorisparalleltothedislocationline.Self-interstitial自間隙的Ahostatomorionthatispositionedonaninterstitiallatticesite.Solidsolution固溶體Ahomogeneouscrystallinephasethatcontainstwoormorechemicalspecies.Bothsubstitutionalandinterstitialsolidsolutionsarepossible.Solute溶質(zhì)Onecomponentorelementofasolutionpresentinaminorconcentration.Itisdissolvedinthesolvent.Solvent溶劑Thecomponentofasolutionpresentinthegreatestamount.Itisthecomponentthatdissolvesasolute.Stoichiometry化學(xué)計(jì)量學(xué)Forioniccompounds,thestateofhavingexactlytheratioofcationstoanionsspecifiedbythechemicalformula.Substitutionalsolidsolution置換固溶體Asolidsolutionwhereinthesoluteatomsreplaceorsubstituteforthehostatoms.Transmissionelectronmicroscope(TEM)透射電子顯微鏡Vacancy空位Anormallyoccupiedlatticesitefromwhichanatomorionismissing.Weightpercent重量百分?jǐn)?shù)Concentrationspecificationonthebasisofweight(ormass)ofaparticularelementrelativetothetotalalloyweight(ormass).2.Youshouldbeabletodothefollowing1.Describebothvacancyandself-interstitialcrystallinedefects.2.Calculatetheequilibriumnumberofvacanciesinamaterialatsomespecifiedtemperature,giventherelevantconstants.3.Namethetwotypesofsolidsolutions,andprovideabriefwrittendefinitionand/orschematicsketchofeach.4.NameanddescribeeightdifferentionicpointdefectsthatarefoundInceramiccompounds.5.Giventhemassesandatomicweightsoftwoormoreelementsinametalalloy,calculatetheweightpercentandatomicpercentforeachelement.6.Foreachofedge,screw,andmixeddislocations:(a)describeandmakeadrawingofthedislocation;(b)notethelocationofthedislocationline;and(c)indicatethedirectionalongwhichthedislocationlineextends.7.Describetheatomicstructurewithinthevicinityof(a)agrainboundary,and(b)atwinboundary.Chapter5mechanicalpropertiesMakesureyouunderstandlanguageandconceptsAnelasticity滯彈性Anelasticdeformation.Time-dependentelastic(nonpermanent)deformation.Charpytest簡(jiǎn)支梁試驗(yàn)Oneoftwotests(seealsoIzodtest)thatmaybeusedtomeasuretheimpactenergyornotchtoughnessofastandardnotchedspecimen.Animpactblowisimpartedtothespecimenbymeansofaweightedpendulum.Ductility延展性Ameasureofamaterial’sabilitytoundergoappreciableplasticdeformationbeforefracture;itmaybeexpressedaspercentelongation(%EL)orpercentreductioninarea(%RA)fromatensiletest.Elasticdeformation彈性變形Deformationthatisnonpermanent,thatis,totallyrecovereduponreleaseofanappliedstress.Elasticrecovery彈性恢復(fù)Nonpermanentdeformationthatisrecoveredorregaineduponthereleaseofamechanicalstress.Engineeringstrain工程應(yīng)變Thechangeingaugelengthofaspecimen(inthedirectionofanappliedstress)dividedbyitsoriginalgaugelength.Engineeringstress工程應(yīng)力Theinstantaneousloadappliedtoaspecimendividedbyitscross-sectionalareabeforeanydeformation.Hardness硬度Themeasureofamaterial’sresistancetodeformationbysurfaceindentationorbyabrasion.Impactenergy沖擊能Ameasureoftheenergyabsorbedduringthefractureofaspecimenofstandarddimensionsandgeometrywhensubjectedtoveryrapid(impact)loading.CharpyandIzodimpacttestsareusedtomeasurethisparameter,whichisimportantinassessingtheductileto-brittletransitionbehaviorofamaterial.Izodtest懸臂梁試驗(yàn)Oneoftwotests(seealsoCharpytest)thatmaybeusedtomeasuretheimpactenergyofastandardnotchedspecimen.Animpactblowisimpartedtothespecimenbyaweightedpendulum.Modulusofelasticity彈性模量Theratioofstresstostrainwhendeformationistotallyelastic;alsoameasureofthestiffnessofamaterial.Plasticdeformation塑性變形Deformationthatispermanentornonrecoverableafterreleaseoftheappliedload.Itisaccompaniedbypermanentatomicdisplacements.Poisson’sratio泊松比Forelasticdeformation,thenegativeratiooflateralandaxialstrainsthatresultfromanappliedaxialstress.Shear剪切Aforceappliedsoastocauseortendtocausetwoadjacentpartsofthesamebodytosliderelativetoeachother,inadirectionparalleltotheirplaneofcontact.Tensilestrength拉伸強(qiáng)度Themaximumengineeringstress,intension,thatmaybesustainedwithoutfracture.Oftentermedultimate(tensile)strength.Toughness韌性Ameasureoftheamountofenergyabsorbedbyamaterialasitfractures.Toughnessisindicatedbythetotalareaunderthematerial’stensilestress–straincurve.Yielding屈服Theonsetofplasticdeformation.Yieldstrength屈服強(qiáng)度Thestressrequiredtoproduceaveryslightyetspecifiedamountofplasticstrain;astrainoffsetof0.002iscommonlyused.2．youshouldbeabletodothefollowing1.Defineengineeringstressandengineeringstrain.2.StateHooke'slaw,andnotetheconditionsunderwhichitisvalid.3.DefinePoisson'sratio.4.Givenanengineeringstress-straindiagram,determine(a)themodulusofelasticity,(b)theyieldstrength(0.002strainoffset),and(c)thetensilestrength,and(d)estimatethepercentelongation.5.Forthetensiledeformationofaductilecylindricaispecimen,describechangesinspecimenprofiletothepointoffracture.6.Computeductilityintermsofbothpercentelongationandpercentreductionofareaforamaterialthatisloadedintensiontofracture.7.Statethereasonswhyhardnesstestsareperformedmorefrequentlythananyothermechanicaltest.Namethetwomostcommonhardness-testingtechniques.8.Computetheworkingstressforaductilemateriai.Chapter6DeformationandStrengtheningMechanisms1．Makesureyouunderstandlanguageandconcepts:Coldworking冷加工Theplasticdeformationofametalatatemperaturebelowthatatwhichitrecrystallizes.Criticalresolvedshearstress臨界分切應(yīng)力Thatshearstress,resolvedwithinaslipplaneanddirection,whichisrequiredtoinitiateslip.Dislocationdensity位錯(cuò)密度Thetotaldislocationlengthperunitvolumeofmaterial;alternately,thenumberofdislocationsthatintersectaunitareaofarandomsurfacesection.Graingrowth晶粒長(zhǎng)大Theincreaseinaveragegrainsizeofapolycrystallinematerial;formostmaterials,anelevated-temperatureheattreatmentisnecessary.Latticestrain晶格應(yīng)變，晶格畸變Slightdisplacementsofatomsrelativetotheirnormallatticepositions,normallyimposedbycrystallinedefectssuchasdislocations,andinterstitialandimpurityatoms.Recovery回復(fù)Thereliefofsomeoftheinternalstrainenergyofapreviouslycold-workedmetal,usuallybyheattreatment.Recrystallization再結(jié)晶Theformationofanewsetofstrain-freegrainswithinapreviouslycold-workedmaterial;normallyanannealingheattreatmentisnecessary.Recrystallizationtemperature再結(jié)晶溫度Foraparticularalloy,theminimumtemperatureatwhichcompleterecrystallizationwilloccurwithinapproximatelyonehour.Resolvedshearstress分切應(yīng)力Anappliedtensileorcompressivestressresolvedintoashearcomponentalongaspecificplaneanddirectionwithinthatlane.Slip滑移Plasticdeformationastheresultofdislocationmotion;also,thesheardisplacementoftwoadjacentplanesofatoms.Slipsystem滑移系Thecombinationofacrystallographicplaneand,withinthatplane,acrystallographicdirectionalongwhichslip(i.e.,dislocationmotion)occurs.Strainhardening形變硬化Theincreaseinhardnessandstrengthofaductilemetalasitisplasticallydeformedbelowitsrecrystallizationtemperature.Solid-solutionstrengthening固溶強(qiáng)化Hardeningandstrengtheningofmetalsthatresultfromalloyinginwhichasolidsolutionisformed.Thepresenceofimpurityatomsrestrictsdislocationmobility.2．youshouldbeabletodothefollowing1.Describeedgeandscrewdislocationmotionfromanatomicperspective.2.Describehowplasticdeformationoccursbythemotionofedgeandscrewdislocationsinresponsetoappliedshearstresses.3.Defineslipsystemandciteoneexample.4.Describehowthegrainstructureofapolycrystallinemetalisalteredwhenitisplasticallydeformed.5.Explainhowgrainboundariesimpededislocationmotionandwhyametalhavingsmallgrainsisstrongerthanonehavinglargegrains.6.Describeandexplainsolid-solutionstrengtheningforsubstitutionalimpurityatomsintermsoflatticestraininteractionswithdislocations.7.Describeandexplainthephenomenonofstrainhardening(orcoldworking)intermsofdislocationsandstrainfieldinteractions.8.Describerecrystallizationintermsofboththealterationofmicrostructureandmechanicalcharacteristicsofthematerial.9.Describethephenomenonofgraingrowthfrombothmacroscopicandatomicperspectives.Chapter7PhasediagrameMakesureyouunderstandlanguageandconcepts:Austenite奧氏體Face-centeredcubiciron;alsoironandsteelalloysthathavetheFCCcrystalstructure.Cementite滲碳體Ironcarbide(Fe3C).Component組元Achemicalconstituent(elementorcompound)ofanalloy,whichmaybeusedtospecifyitscomposition.Equilibrium平衡Thestateofasystemwherethephasecharacteristicsremainconstantoverindefinitetimeperiods.Atequilibriumthefreeenergyisaminimum.Eutecticphase共晶相Oneofthetwophasesfoundintheeutecticstructure.Eutecticreaction共晶反應(yīng)Areactionwherein,uponcooling,aliquidphasetransformsisothermallyandreversiblyintotwointimatelymixedsolidphases.Eutecticstructure共晶組織Atwo-phasemicrostructureresultingfromthesolidificationofaliquidhavingtheeutecticcomposition;thephasesexistaslamellaethatalternatewithoneanother.Eutectoidreaction共析反應(yīng)Areactionwherein,uponcooling,onesolidphasetransformsisothermallyandreversiblyintotwonewsolidphasesthatareintimatelymixed.Ferrite鐵素體Ceramicoxidematerialscomposedofbothdivalentandtrivalentcations(e.g.,Fe2andFe3),someofwhichareerrimagnetic.Hypereutectoidalloy過共析合金Foranalloysystemdisplayingaeutectoid,analloyforwhichtheconcentrationofsoluteisgreaterthantheeutectoidcomposition.Hypoeutectoidalloy亞共析合金Foranalloysystemdisplayingaeutectoid,analloyforwhichtheconcentrationofsoluteislessthantheeutectoidcomposition.Intermetalliccompound金屬間化合物Acompoundoftwometalsthathasadistinctchemicalformula.Onaphasediagramitappearsasanintermediatephasethatexistsoveraverynarrowrangeofcompositions.Invariantpoint恒定點(diǎn)、三相平衡點(diǎn)Apointonabinaryphasediagramatwhichthreephasesareinequilibrium.Isomorphous勻晶的Havingthesamestructure.Inthephasediagramsense,isomorphicitymeanshavingthesamecrystalstructureorcompletesolidsolubilityforallcompositions.Metastable亞穩(wěn)的Nonequilibriumstatethatmaypersistforaverylongtime.Microstructure顯微組織Thestructuralfeaturesofanalloy(e.g.,grainandphasestructure)thataresubjecttoobservationunderamicroscope.Pearlite珠光體Atwo-phasemicrostructurefoundinsomesteelsandcastirons;itresultsfromthetransformationofausteniteofeutectoidcompositionandconsistsofalternatinglayers(orlamellae)ofα-ferriteandcementite.Peritecticreaction包晶反應(yīng)Areactionwherein,uponcooling,asolidandaliquidphasetransformisothermallyandreversiblytoasolidphasehavingadifferentcomposition.Phase相Ahomogeneousportionofasystemthathasuniformphysicalandchemicalcharacteristics.Phasediagram相圖Agraphicalrepresentationoftherelationshipsbetweenenvironmentalconstraints(e.g.,temperatureandsometimespressure),composition,andregionsofphasestability,ordinarilyunderconditionsofequilibrium.Phaseequilibrium相平衡Proeutectoidcementite先共析滲碳體Primarycementitethatexistsinadditiontopearliteforhypereutectoidsteels.Proeutectoidferrite先共析鐵素體Primaryferritethatexistsinadditiontopearliteforhypoeutectoidsteels.Solubilitylimit溶解度極Themaximumconcentrationofsolutethatmaybeaddedwithoutforminganewphase.2．youshouldbeabletodothefollowing1.(a)Schematicallysketchsimpleisomorphousandeutecticphasediagrams.(b)Onthesediagramslabelthevariousphaseregions.(c)Labelliquidus,solidus,andsolvuslines.2.Givenabinaryphasediagram,thecompositionofanalloy,itstemperature,andassumingthatthealloyisatequilibrium,determine:(a)whatphase(s)is(are)present;(b)thecomposition(s)ofthephase(s).3.Forsomegivenbinaryphasediagram,dothefollowing:(a)locatethetemperaturesandcompositionsofalleutectic,eutectoid,peritectic,andcongruentphasetransformations;and(b)writereactionforallthesetransformationsforeitherheatingorcooling.4.Giventhecompositionofaniron-carbonalloycontainingbetween0.022wt%Cand2.14wt%C,beableto(a)specifywhetherthealloyishypoeutectoidorhypereutectoid;(b)nametheproeutectoidphase;and(c)makeaschematicdiagramofthemicrostructureatatemperaturejustbelowtheeutectoid.Chapter8Phasetransformation1．Makesureyouunderstandlanguageandconcepts:Annealing退火Agenerictermusedtodenoteaheattreatmentwhereinthemicrostructureand,consequently,thepropertiesofamaterialarealtered.‘‘Annealing’’frequentlyreferstoaheattreatmentwherebyapreviouslycold-workedmetalissoftenedbyallowingittorecrystallize.Austenitizing奧氏體化Formingaustenitebyheatingaferrousalloyaboveitsuppercriticaltemperature—towithintheaustenitephaseregionfromthephasediagram.Bainite貝氏體Anaustenitictransformationproductfoundinsomesteelsandcastirons.Itformsattemperaturesbetweenthoseatwhichpearliteandmartensitetransformationsoccur.Themicrostructureconsistsofα-ferriteandafinedispersionofcementite.Coarsepearlite粗珠光體Pearliteforwhichthealternatingferriteandcementitelayersarerelativelythick.Finepearlite細(xì)珠光體Pearliteforwhichthealternatingferriteandcementitelayersarerelativelythin.Fullannealing完全退火Forferrousalloys,austenitizing,followedbycoolingslowlytoroomtemperature.Isothermaltransformationdiagram等溫轉(zhuǎn)變圖Aplotoftemperatureversusthelogarithmoftimeforasteelalloyofdefinitecomposition.Usedtodeterminewhentransformationsbeginandendforanisothermal(constant-temperature)heattreatmentofapreviouslyaustenitizedalloy.Martensite馬氏體Ametastableironphasesupersaturatedincarbonthatistheproductofadiffusionless(athermal)transformationfromaustenite.Normalizing正火Forferrousalloys,austenitizingabovetheuppercriticaltemperature,thencoolinginair.Theobjectiveofthisheattreatmentistoenhancetoughnessbyrefiningthegrainsize.Nucleation形核率Theinitialstageinaphasetransformation.Itisevidencedbytheformationofsmallparticles(nuclei)ofthenewphase,whicharecapableofgrowing.Phasetransformation相變Achangeinthenumberand/orcharacterofthephasesthatconstitutethemicrostructureofanalloy.Precipitationhardening沉淀強(qiáng)化（agehardening時(shí)效強(qiáng)化）Hardeningandstrengtheningofametalalloybyextremelysmallanduniformlydispersedparticlesthatprecipitatefromasupersaturatedsolidsolution;sometimesalsocalledagehardening.Precipitationheattreatment沉淀熱處理Aheattreatmentusedtoprecipitateanewphasefromasupersaturatedsolidsolution.Forprecipitationhardening,itistermedartificialaging.Solutionheattreatment固溶處理Theprocessusedtoformasolidsolutionbydissolvingprecipitateparticles.Often,thesolidsolutionissupersaturatedandmetastableatambientconditionsasaresultofrapidcoolingfromanelevatedtemperature.Spheroidite球狀珠光體Microstructurefoundinsteelalloysconsistingofspherelikecementiteparticleswithinanα-ferritematrix.Itisproducedbyanappropriateelevated-temperatureheattreatmentofpearlite,bainite,ormartensite,andisrelativelysoft.Spheroidizing球化Forsteels,aheattreatmentcarriedoutatatemperaturejustbelowtheeutectoidinwhichthespheroiditemicrostructureisproduced.Supercooling過冷Coolingtobelowaphasetransitiontemperaturewithouttheoccurrenceofthetransformation.Superheating過熱Heatingtoaboveaphasetransitiontemperaturewithouttheoccurrenceofthetransformation.Temperedmartensite回火馬氏體Themicrostructuralproductresultingfromatemperingheattreatmentofamartensiticsteel.Themicrostructureconsistsofextremelysmallanduniformlydispersedcementiteparticlesembeddedwithinacontinuousα-ferritematrix.Toughnessandductilityareenhancedsignificantlybytempering.Thermallyactivatedtransformation熱激活轉(zhuǎn)變Areactionthatdependsonatomicthermalfluctuations;theatomshavingenergiesgreaterthananactivationenergywillspontaneouslyreactortransform.TherateofthistypeoftransformationdependsontemperatureaccordingtoEquation10.3.Transformationrate轉(zhuǎn)變速率Thereciprocalofthetimenecessaryforareactiontoproceedhalfwaytoitscompletion.2．youshouldbeabletodothefollowing：1.Brieflydescribethemicrostructureforeachofthefollowingmicroconstituentsthatarefoundinsteelalloys:finepearlite,coarsepearlite,spheroidite,bainite,martensite,andtemperedmartensite.2.Citethegeneralmechani