专业课课件中文版2第二章

1913年，年轻的丹麦物理学家玻尔在总结（.hrdigr188-19）在926直角坐标xy，z或者极坐标rθ，N，O，P

（n-空间给定方向上的分量是量子化的;m±=0,±1,2,…,±ι。1±2Pauli ENFNdrFAdrFRdrEA 孤电靠并生氢键形成的条件是必须在分子中存在电负性很强的元素导致分子间的作用力称为Vanderwaals键。Atomicmassunit(amu):原子质量单位number:Atomicweight:Bohratomicmodel:波Bondingenergy:键能Coulombic:库仑力Covalentbond:共价键Dipole(electric):偶极electronicconfiguration:电子构型electron电Electronegative:负电的Electropositive:正电Groundstate:基态Hydrogenbond:氢Ionicbond:离子键Isotope:同位素分子Metallicbond:Mole:摩尔Pauliexclusionprinciple:泡利不相Periodictable:元素周期表Polarmolecule:极Primarybonding:强 Quantum量子力

电子数为4。亚金属Ge。例6、A和B元间键合中离子特性所占的百分IC(%)[1e025(AB)2式中xAxB分别为A和B元素的电负性值。已Ti，O，InSb的电负性分别1.5，3.5，1.71.9，试计算TiO2和InSb的IC（%）解：对 Quantumnumber:量子数 bonding:弱键valenceelectron:价电子vanderwaalsbond:

6310 Wave-mechanicalmodel:波粒二象性模型

1、原mi和自旋角动量量子数si。2、在多电子的原子中，核外电子的排布应遵循答：能量最低原理，PauliHund例

在多少个原子？②lg中含有多少个原子？属Ge。解：① 的相对分子质 中所含原子 原子结构有什么共同特点？从左到右或从上到下

.101

但从左→右，核电荷依次增多，原子半 ② 中所含原子数得电子能力增加，金属性减弱，非金属

5

（或分子）的

长方形。密排六方的晶胞参数有两个，a为正六边形的边长，c为上下底面的间距（晶胞高度ca

VCNA要1、晶体和晶胞2金属原子之间靠金属键结合形成的晶体为金六个面中心各有一个原子，角上的原子为8个晶胞所共有，每个面中心原子为2个晶胞所共有。与原子半径R之间的关系为：2a23晶胞的中心有一个原子，角上的原子为8个晶胞所共有，所以，体心立方晶胞中的原子数为2。晶胞长度a（晶胞参数a=b=c）与原子半径R之间3a晶胞中原子堆积系数

堆积方式取决于阴阳离子的电荷和离子半径r的相与它直接相邻的异号离子或原子的个数称为配位n(ACAAVCNA（Z长度ab，cαβγ这67如表3.6，同的要求用数学方法确定只能有14种空归属于7系中（附图，表。，Y、Z出。±whklhkl（hkl

非晶态固体指原子在空间排布上没有长程有推导面心立方和体心立方结构晶体中的晶胞边长2312323123

之间的夹角为

（hkil（对晶向指数[u`v`w`]与[uvtw]之间的转换为：积方式有六方最紧密堆积和面心立方最紧密堆积周围有86n个，八面体间隙为n

知道为什么体心立方结构和六方密堆积结构是最Allotropy:同素异形现象Amorphous:无定形Anion:Anisotropy:各向异性atomicpackingbody-centeredcubic(BCC):体心立方结构Bragg’slaw:布拉格定律Cation:阳离 coordinationnumber:配位crystalstructure:晶体结crystalsystem:晶系crystalline:晶体的衍face-centeredcubicFCC):面心立方结例1.纯铝晶体为面心立方点阵，已知铝的相对原子质量Ar（Al）=26.97，原R=0.143nm，求子，点镇常数a可由原子半径求得。a22R220.143nm

Ar(Al)

1N0a4

16.023104

3)33

n1/V1=n2/2铝为一立方结构，α0=0.4049nm，在一个厚度晶胞？该薄片质量为0.3378g，问该薄片有多少

式中面心立方结构n1=4，体心立方结n2=2，162R1162R1

R2

R333113929283V(0.4049)30.06638nm

.c

。 常数可得薄片中Al原子数

3.81n个

6.0210

（2 3.80.33786.021023/26.987.53103.8

mm3/g×1.12×1020根据薄片中的原子数和单位晶胞数可求得单位晶胞中的铝原子数l为：n因此Al单位晶胞由43.对于具有面心立方结构和体心立方结构的同211V1=a3=(22R)3 211

子半径RO-2=0.140nm。O氯化钠的晶体结构如图1-1a=2（RMg+2+R-2）=2（0.066+0.140）O每一个单位晶胞中含有4Mg+2O-2；1molMg+2具有24.31g

质量，1mol的O-2具有16.00g2V2=a2

3333

密度

6.0210a

6.021023 424.31g 3.83g/cm3 0.412107cm36.02石墨的体

2.25g/

它是立方体的，试确定其晶体结构为多径为0.1429nm；离子半径为0.068nm

V2V1

16.6103g/

例8.bcc铁的单位晶胞体912是解：（1 180.95g/6.02

0.0486nm3。当铁由bcc转变成fcc时，其密度改4原子的堆积密度 43

55.85g/6.021023

7.钻石（2-1）的晶格常a=0.357nm，当

ρfcc

55.85g/6.0210230.04861021

100%立方晶系中下列晶面和晶向13（321[010][01][11]，1]2-1从图2-1共有8个碳原子A=0.357nm，1mol的C具有质量12g，钻石的8 0.357107cm36.0210对于1g碳，钻石的体

2-2立方晶系中的一些晶面和晶13.505g/

OB为[011]

321如图2-2（c）所示。GH为[010]，GD为[111]。2-2（d）所示。OM为[31]，ON为[231]106个表面面心位置的坐标。6个面心构成一个正八面体，这个八面解：2-3所示。2-3中A，B，C，D，E，F为立方晶胞中6个表面ABF面平行CDE面，其晶面指数为（11ABE面平行CDF面，其晶面指数为（1

图2-4六方晶体中常见2-5晶（2）图2-5中，OA晶向的确定11在六方晶体中 （1120（

沿各方向移动距离化为最小整数即可3]12在面心立方和体心立方中，最密排的平面的 求出图2-5中所示晶向的晶向指数 （100（01013有一个AB型面心立方结构的晶格，密度

构 nMN03a0=3V3

46.021023

covalentbonds:共价键hydrogen氢vanderWaalsbonds:键（分子键）methane(CH4)甲烷Hydrocarbons:烃:由碳和氢组成的物EthyleneC2H4乙在面心立方密堆中原子半径与晶格参数之间下关系2 2式中R为原子半径。设原子间距为a2则 22结

acetyleneC2H2乙炔UnsaturatedHydrocarbons:不饱和烃SaturatedHydrocarbons:饱和烃石Macromolecule:高分子Isomerism:同质Mer:链节:组成聚合物链重复单位的原子Polymer:聚合物，由小重复单元（链Monomer:单体:由一个简单链节组成的PolyethylenePE)聚乙(PTFE):聚四氟乙烯Polyvinylchloride(PVC):聚氯乙烯PolypropylenePP):Polystyrene(PS):聚苯乙PolymethylmethacrylatePMMA):聚甲基Phenol-formaldehydeKakelite):（电木Polyhexamethyleneadipamide(nylon尼龙PolyethyleneterephthalatePETapolyester):聚乙烯对苯二酸酯Polycarbonate:聚碳酸酯Homopolymer(均聚物):由相同链节组成Copolymer(共聚物):由两种或多种不同Bifunctional(二功能的):Trifunctionalmer(三功能的):链节单位具MolecularWeight:分子Thenumber-averagemolecularweight:数式中：Mi:分子量在某范围内的weight-averagemolecularweight:质(重)均式中：Mi:xi:具有相同间隔分子量范围

2、习题聚丙烯的数均分子量为1,000,000g/mol.计算m=3(AC)+6(AH)=(3)(12.01g/mol)(6)(1.008g/mol)=42.08 106g/Degreeofpolymerization(n):聚合度(n)

n n

42.08g/

LinearPolymers:线型聚合物BranchedPolymers:支链型聚合物CrosslinkedPolymers:交联型聚合物NetworkPolymers:网络型ThermosticPolymers:热塑性聚合物ThermosettingPolymers:热固型聚合物

3、习题均分子量(b)质均分子量(c)数均聚合度(d)质解从数据表我们可以计算数量平均分子量Mn其中c:全部为晶体时的密度s:具有部分晶体聚合物的密度

1例题 均分子量(b)数均聚合度(c)质均分子量

Mnxi

=xiMi=33040Mnxi

=21150

重量分子量(a)(略CHm=3(A)+6(A)=(3)(12.01g/mol)CH聚氯乙烯链节中原子CH和Cl

(6)(1.008g/mol)=42.08量分别为12.01,1.0135.45所以m=2(12.01g/mol3(1.01g/mol

nMn

42.08g/

785nMn

21150g/mol33862.50g/mol

(d)参照(c)(略35.45g/mol=62.504.3b

4、习题MwwiMi

LNdsin(2

NN

r

解：首先计算

6、习题4.28计算具有完全晶体结构的聚乙烯的密原所以m2(AC4(AF2)(12.01g/mol

VcNA(4)(19.00g/mol)=100.02则

nn=2A为链节的分子量聚乙烯链节的分子量A=2(AC)+4(AH)=nMn

100.2g/

(2)(12.01g/mol)+(4)(1.008g/mol)=28.05g/molVC代表单胞的体积等于晶胞三个边长的乘积（见

所 Vc

进一步假设一个C-C键长d0.154nm=109o见4.4节则

0.998g/LNd

)2

Nr N5、习题

m=12(AC)+14(AH)=(12)(12.01g/mol)(14)(1.008g/mol)=158.23

nMn

158.23g/

Alloy:Ametallicsubstancethatiscomposedoftwoormore(Concentrationspecificationonthebasisofweight(ormass)ofaparticularelementrelativetothetotalalloyweight(ormass).Stoichiometry:Forioniccompounds,thestateofhavingexactlytheratioofcationstoanionsspeci-fiedbythechemicalImperfection:Adeviationfromperfection;normallyappliedtocrystallinematerialswhereinthereisadeviationfromatomic/molecularorderand/orcontinuity.Pointdefect:Acrystallinedefectassociatedwithoneor,atmost,severalatomicsites.Vacancy:Anormallyoccupiedlatticesitefromwhichanatomorionismissing.

Vacancydiffusion:Thediffusionmechanismwhereinnetatomicmigrationisfromlatticesitetoanadjacentvacancy.Self-interstitial:Ahostatomorionthatispositionedonaninterstitiallatticesite.Schottkydefect:缺Inanionicsolid,adefectconsistingofacation–vacancyandanion–vacancypair.Thevibrationofanatomaboutitsnormalpositionina材料中原子在其平衡位置附近的振动。一般说Substitutionalsolidsolution:Asolidsolutionwhereinthesoluteatomsreceorsubstituteforthehostatoms.Interstitialdiffusion:Adiffusionmechanismwherebyatomicmotionisfrominterstitialsitetointerstitialsite.Interstitialsolidsolution:Asolidsolutionwhereinrelativelysmallsoluteatomsoccupyinterstitialpositionsbetweenthesolventorhost相对尺寸较小的溶质原子占据溶剂或晶格原Solidsolution:Ahomogeneouscrystallinephasethatcontainstwoormorechemicalspecies.BothsubstitutionalandinterstitialsolidsolutionsareSolid-solutionstrengthening:固溶体强化Hardeningandstrengtheningofmetalsthatresultfromalloyinginwhichasolidsolutionisformed.Thepresenceofimpurityatomsrestrictsdislocation由于形成固溶体的合金化过程引起的金属硬Solute:Onecomponentorelementofasolutionpresentinaminorconcentration.ItisdissolvedintheSolutionheattreatment:固溶处理，均匀化退火Theprocessusedtoformasolidsolutionbydissolvingprecipitateparticles.Often,thesolidsolutionissupersaturatedandmetastableatambientconditionsasaresultofrapidcoolingfromanelevatedtemperature.Solvent:ThecomponentofasolutionpresentinthegreatestItisthecomponentthatdissolvesaBurgersvectorb):Avectorthatdenotesthemagnitudeanddirectionoflatticedistortionassociatedwithadislocation.表示

CompositionCi):Therelativecontentofaparticularelementorconstituent(i)withinanalloy,usuallyexpressedinweightpercentoratompercent.Defectstructure:Relatingtothekindsandconcentrationsofvacanciesandinterstitialsinaceramiccompound.Dislocation:Alinearcrystallinedefectaroundwhichthereisatomicsticdeformationcorrespondstothemotionofdislocationsinresponsetoanappliedshearstress.Edge,screw,andmixeddislocationsarepossible.在外加切应力作用下位错的运动可以导致晶Screwdislocation:Alinearcrystallinedefectassociatedwiththelatticedistortioncreatedwhennormallyparallelnesarejoinedtogethertoformahelicalramp.heugrsecorsprlelotheiloaionlne.平行的相邻晶面之间依次错粘合在一起形成的螺Mixeddislocation:AdislocationthathasbothedgeandscrewDislocationdensity:Thetotaldislocationlengthperunitvolumeofmaterial;alternay,thenumberofdislocationsthatintersectaunitareaofarandomsurfacesection.Dislocationline:Thelinethatextendsalongtheendoftheextrahalf-neofatomsforanedgedislocation,andalongthecenterofthespiralofascrewdislocation.Edgedislocation:Alinearcrystallinedefectassociatedwiththelatticedistortionproducedinthevicinityoftheendofanextrahalfneofatomswithinacrystal.TheBurgersvectorisperpendiculartothedislocation存在的多余半原子面的末端附近区域所形成的原Electroneutrality:Thestateofhavingexactlythesamenumbersofpositiveandnegativeelectricalcharges(ionicandelectronic),thatis,ofbeingelectricallyneutral.Frenkeldefect:缺Inanionicsolid,acation–vacancyandcation–interstitialpair.在离子固体中的阳离子-空位对和阳离子-间隙原对Grain:AnindividualcrystalinapolycrystallinemetalorGrainboundary:Theinterfaceseparatingtwoadjoininggrainshavingdifferentcrystallographicorientations.把两个相邻具有不同晶体学取向的晶粒分离

Graingrowth:Theincreaseinaveragegrainsizeofapolycrystallinematerial;formostmaterials,anelevated-temperatureheattreatmentisnecessary.Grainsize:Theaveragegraindiameterasdeterminedfromarandomcrosssection.Microscopy:Theinvestigationofmicrostructuralelementsusingsometypeofmicroscope.用某种类型的显微镜对材料微观组织情况进Microstructure:Thestructuralfeaturesofanalloy(e.g.,grainandphasestructure)thataresubjecttoobservationunderaPhotomicrograph:显微组织Thephotographmadewithamicroscope,whichrecordsamicrostructuralimage.在显微镜下拍摄，记录显微组织结构形态的Scanningelectronmicroscope:Amicroscopethatproducesanimagebyusinganelectronbeamthatscansthesurfaceofaspecimen;animageisproducedbyreflectedelectronbeams.Examinationofsurfaceand/ormicrostructuralfeaturesathighmagnificationsispossible.应用使对样品的表面特征和显微组织特征进行高Scanningprobemicroscope:扫描探针显微镜，Amicroscopethatdoesnotproduceanimageusinglightradiation.Rather,averysmallandsharpproberasterscansacrossthespecimensurface;out-of-surfacenedeflectionsinresponsetoelectronicorinctionswiththeprobearemonitored,from

Nexp(Qvv vexp(Qv

atopographicalmapofthespecimensurface(onnanometerscale)is

(8.62105eV/K)(1273K)Transmissionelectronmicroscope:透射电子显微Amicroscopethatproducesanimagebyusingelectronbeamsthataretransmitted(passthrough)thespecimen.Examinationofinternalfeaturesathighmagnificationsispossible.透射电子显微镜是用穿过样品的透射产Calculatetheequilibriumnumberofvacanciespercubicmeterforcopperat1000℃.Theenergyforvacancyformationis0.9eV/atom;theatomicweightanddensity(at1000°C)forcopperare63.5g/moland8.40g/cm3,respectively.NNexp(Qv NAexp(Qv

2.74由此可见材料中缺陷数是一个非常大的绝对5.28CopperandtinumbothhavetheFCCcrystalstructureandCuformsasubstitutionalsolidsolutionforconcentrationsuptoapproximay6wt%Cuatroomtemperature.Computetheunitcelledgelengthfora95wt%Pt-5wt%Cualloy.5.29CitetherelativeBurgersvector–dislocationlineorientationsforedge,screw,andmixed5.31(a)Thesurfaceenergyofasinglecrystaldependsonthecrystallographicorientationwithrespecttothesurface.Exinwhythisisso.(b)ForanFCCcrystal,suchasaluminum,wouldyouexpectthesurfaceenergyfora(100)netobegreaterorlessthanthatfora(111)ne?Why?DesignD1*Aluminum-lithiumalloyshavebeendevelopedbytheaircraftindustryinordertoreducetheweightandimprovetheperformanceofitsaircraft.Acommercialaircraftskinmaterialhavingadensityof2.55g/cm3isdesired.ComputetheconcentrationofLi(inwt%)thatisrequired.5.D2*IronandvanadiumbothhavetheBCCcrystalstructureandVformsasubstitutionalsolidsolutioninFeforconcentrationsuptoapproximay20wt%Vatroomtemperature.DeterminetheconcentrationinweightpercentofVthatmustbeaddedtoirontoyieldaunitcelledgelengthof0.289nm. (6.0231023atoms/mol)(8.40g/cm3

第六63.5g/2.21025vacancies/Farther

()用方程的形式写出菲克第一定律和第二定(b)每个方程通常用在什么类型的扩散中写出金属和离子固体扩散机制的一个不同之处。Diffusion:MasstransportbyatomicDiffusionfluxJ):Thetyofmassdiffusingthroughandperpendiculartoaunitcross-sectionalareaof

perunit单位时间内通过一个垂直与扩散方向上单位横截DiffusioncoefficientD):TheconstantofproportionalitybetweenthediffusionfluxandtheconcentrationgradientinFick’sfirstlaw.ItsmagnitudeisindicativeoftherateofatomicFick’sfirstlaw:菲克第一定律，扩散第一定律ThediffusionfluxisproportionaltotheconcentrationThisrelationshipisemployedforsteady-statediffusionFick’ssecondlaw:菲克第二定律，扩散第二定律Thetimerateofchangeofconcentrationisproportionaltothesecondderivativeofconcentration.Thisrelationshipisemployedinnonsteady-statediffusionsituations.Steady-statediffusion:Thediffusionconditionforwhichthereisnonetaccumulationordepletionofdiffusingspecies.Thediffusionfluxisindependentof扩散组元既没有净堆积也没有净的扩散过程Nonsteady-statediffusion:Thediffusionconditionforwhichthereissomenetaccumulationordepletionofdiffusingspecies.Thediffusionfluxisdependenton扩散过，扩散组元存在净堆积或净的扩散Self-diffusion:AtomicmigrationinpureInterstitialdiffusion:Adiffusionmechanismwherebyatomicmotionisfrominterstitialsitetointerstitialsite.Vacancydiffusion:isfromlatticesitetoanadjacentvacancy.ActivationenergyQ):Theenergyrequiredtoinitiateareaction,suchasCarburizing:Theprocessbywhichthesurfacecarbonconcentrationofaferrousalloyisincreasedbydiffusionfromthesurroundingenvironment.Component:Achemicalconstituent(elementorcompound)ofanalloy,whichmaybeusedtospecifyitscomposition.tospecifycompleythecompositionofallphasesofachemicalsystem.CompositionCiConcentration:Therelativecontentofaparticularelementorconstituent(i)withinanalloy,usuallyexpressedinweightpercentoratompercent.Alsocall

ConcentrationgradientdC/dx):TheslopeoftheconcentrationprofileataspecificConcentrationprofile:Thecurvethatresultswhentheconcentrationofachemicalspeciesisplottedversuspositioninamaterial.Interdiffusionimpuritydiffusion:Diffusionofatomsofonemetalintoanother一种金属中的原子向另一种金属中的扩散叫互扩EXAMPLEPROBLEM6.2Consideronesuchalloythatinitiallyhasauniformcarbonconcentrationof0.25wt%andistobetreatedat950℃(1750℉).Iftheconcentrationofcarbonatthesurfaceissuddenlybroughttoandmaintainedat1.20wt%,howlongwillittaketoachieveacarboncontentof0.80wt%ataposition0.5mmbelowthesurface?Thediffusioncoefficientforcarboninironatthistemperatureis1.6X10-11m2/s;assumethatthesteelpieceissemi-infinite.C0=0.25wt%CCs=1.20wt%CCx=0.80wt%x=0.50mm=5X10-4D=1.6X10-11 C

Cs0 Cs0

5104

度1

曲强度 62.5s12t0.4210erf t erf=0.4210的数据，我们采用相连数ZerfZ

Anelasticity:Inmostengineeringmaterials,elasticdeformationwillcontinueafterthestressapplication,anduponloadreleasesomefinitetimeisrequiredforcompleterecovery.Thistime-dependentelasticz

0.4210

behaviorisknownas

z第七章

Designstress:设计应Forstaticsituationsandwhenductilematerialsareused,designstress,σd,istakenasthecalculated陈述Hooke定律，并且保证定律有效所遵模量；(b)屈服强度（残余应变0.002时）；

stresslevelσc(onthebasisoftheestimatedumload)multipliedbyadesignfactor,N',thatisσd=N'σc,whereN'isgreaterthanunity.力σd是计算的应力σc（即估算的最大载荷）一个设计因子N'，即σdN'σcN'1Ductility:延伸Ductilityisameasureofthedegreeofsticdeformationthathasbeensustainedatfracture.Elasticdeformation:弹性形Deformationinwhichstressandstrainareproportionaliscalledelasticdeformation.Elasticdeformationisnonpermanent,whichmeanswhentheappliedloadisreleased,thepiecereturnstoitsoriginalshape.ElasticrecoveryElasticrecoverymeansthatwhentheappliedloadisreleased,thepiecereturnstoitsoriginalshape.Elastomer:弹性Elastomerisaclassofpolymerswhosedeformationdisyedbystrain-stresscurveistotallyelastic,i.e.,largerecoverablestrainsproducedatlowstresslevels.Engineeringstrain:工程应Engineeringstrainεisdefinedaccordingtoε=(li-l0)/l0=Δl/l0,inwhichl0istheoriginallengthbeforeanyloadisapplied,andliistheinstantaneouslength.Sometimesthetyli-l0isdenotedasΔl,andisthedeformationelongationorchangeinlengthatsomeinstant,asreferencedtotheoriginallength.Engineeringstrainisunitless.工程应变εεli-l0)/l0Δl/l0定义，这里是样品加载前的初始长度，li是加载瞬间的长度，有时li-l0也用Δl来表示，即代表与初始长度相比:Engineeringstressσisdefinedbytherelationshipσ=F/A0,inwhichFistheinstantaneousloadappliedperpendiculartothespecimencrosssection,inunitsofnewtons(N),andA0istheoriginalcross-sectionalareabeforeanyloadisapplied(m2).Theunitsofengineeringstressaremegapascals,MPa.

工程应力σ的定义为σ=F/A0F是加载在垂直样品横截面的瞬间载荷，单位为，A0是加载前样品的初始横截面积（单位m2），工程应力单位为MPa。Flexuralstrength:抗弯强Forthebrittleceramicmaterials,flexuralstrengthsaredeterminedbythestressatfractureintransversebendingtests.Hardness:硬Hardnessisameasureofthe tolocalizesticdeformation.Modulusofelasticity:弹性模Formostmetalsthatarestressedintensionandatrelativelylowlevels,stressandstrainareproportionaltoeachotherthroughtherelationshipσ=Eε.ThisisknownasHooke’slaw,andtheconstantofproportionalityE(GPa)isthemodulusofelasticity,orYoung’smodulus.正比关系，可表达为σ=Eε，这就是定理，比例常数E（GPa）就是弹性模量，或杨氏模量。sticdeformation:塑性形Asthematerialisdeformedbeyondthestrainthatelasticdeformationpersists,thestressisnolongerproportionaltostrain,andpermanent,nonrecoverable,orsticdeformationoccurs.Poisson’sratio:Poisson’sratiorepresentsthenegativeratiooftransverseandlongitudinalstrains.Proportionallimit:比例极Formetalsthatexperiencethegradualelastic-stictransition,thepointofyieldingisdeterminedastheinitialdeparturefromlinearityofthestress-straincurveandthisissometimescalledtheproportionallimit.Resilience:弹Resilienceisthecapacityofamaterialtoabsorbenergyduringelasticdeformation.Safestress:安全Safestressisbasedontheyieldingstrengthofthematerialandisdefinedastheyieldstrengthdividedbyafactorofsafety,N,orσw=σy/N.强度除以一个安全因子N，或σw=σy/NTensilestrength:抗拉强Tensilestrengthcorrespondstotheumtensilestressthatmaybesustainedbyaspecimen.Toughness:韧Toughnessisameasureoftheabilityofamaterialtoabsorbenergyuptofracture.Truestrain:真应TruestainεTisdefinedbyεT=ln(li/l0),inwhichl0istheoriginallengthbeforeanyloadisapplied,andliistheinstantaneouslength.真应变εT的定义为εT=ln(li/l0)l0是样品加载前的初始长度，li是瞬间长度。Truestress:真应TruestressσTisdefinedastheloadFdivided

:Yieldingstrengthisindicativeofthestressatwhichsticdeformationbegins.7.1一个铜板最初长度为305nm276MPa的应力的拉伸，假如发生的形变是完全解因为形变是弹性的，根据7.5，应变与应力有关，更进一步说，通过7.2ε=(li-l0)/l0=Δl/l0，伸长值Δl与初始长度l0有关。结合这两个表达式，可以解得Δl有：E(llEσ和l0276MPa305mm，由可知铜的杨氏模量E110GPa，将以上值代l(276MPa)(305mm)1101037.2在一个直径为10mm的圆柱型黄铜棒为完全弹性，那么使得直径产生2.5×10-3mm的改解当作用力F被施加到样品上时，样品在Z方向将被拉长，同时直径在x方向上将减少在xtheinstantaneouscross-sectionalareaAioverwhichdeformationisoccurring,orσT=F/Ai.真应力σT定义为形变发生时，载荷F

dxd0

2.5103

2.5Ai的比值，或者σTF/AiYielding:屈Formetals,thephenomenonofyieldingoccurs

随后应用7.8计算Z方向的应变。黄铜的泊松比为0.34，因此theonsetofsticorpermanent

x

(2.5104)

7.3510应用7.5和弹性模量可以计算施加的d

12.8103力，弹性模量如表7.197GPa

F

(0)2(450106N/m2

E(7.35104)(97103MPa)为了计 7.2中的长度变化l，我最后， 7.1可以确定所施加的力为d

F

(0)22

10103

在应力－应变曲线上定位应力点A，从应变轴上(71.3106N/m2)

2ll0(0.06)(250mm)7.3由图7.12所给出的黄铜样品的拉伸应残余应变为0.002时的屈服强度12.8mm的圆柱型样品所能承应力345GPa时其长度的变化。解

7.4圆柱形铁样品初始直径为12.8mm，ff 解延展度可由7.12计算始线性部分的斜率。为了便于计算，图7.12插

2 2

10.7mm)2

%RA 100

((

2.22.

真实应力可由方程7.15计算得到，本题Eslope

2

因为线性部分通过原点，则σ1和ε1如果我们选取σ2150MPa，那么ε2

F

A(460106N/m2)(128.7mm2

)0.0016

106E(1500)MPa

F 2r0.0016r此值很接近表7.1中所给的黄铜的弹性模量

(89.9mm2

)

10N/ 97GPa0.002残余应变线已经由插图给出，它与应力－应变曲线的交点大约为250MPa,即为黄铜的样品所能承受的最大负载可由7.1计算得到,方σ是拉伸强度，由图7.12可知,其值为450MPa。解关于最大负载F的方程：

1067.5.利用方程7.19计算合金应变-硬化指数n，其中真实应力为415MPa，所产生真实应变为0.10，假定Ｋ值为1035MPa.解这需要对方程7.19进行代数变换，使n变为关联参数，采用对数变换并重新调整，得n值loglog log(13n log第八章变形和强化机制

Coldworking:冷加工、冷变Thesticdeformationofametalatatemperaturebelowthatatwhichitrecrystallizes.Criticalresolvedshearstresscrss):临界剪切分切应Thatshearstress,resolvedwithinaslipneanddirection,whichisrequiredtoinitiateslip.Dislocationdensity:位错密Thetotaldislocationlengthperunitvolumeofmaterial;alternay,thenumberofdislocationsthatintersectaunitareaofarandomsurfacesection.Graingrowth:Theincreaseinaveragegrainsizeofapolycrystallinematerial;formostmaterials,anelevated-temperatureheattreatmentisnecessary.Latticestrains:Slightdiscementsofatomsrelativetotheirnormallatticepositions,normallyimposedbycrystallinedefectssuchasdislocations,andinterstitialandimpurityatoms.Recovery:回Thereliefofsomeoftheinternalstrainenergyofapreviouslycold-workedmetal,usuallybyheatRecrystallization:再结Theformationofanewsetofstrain-grainswithinapreviouslycold-workedmaterial;normallyanannealingheattreatmentisnecessary.Recrystallizationtemperature:Foraparticularalloy,theminimumtemperatureatwhichcompleterecrystallizationwilloccurwithinapproximayonehour.Resolvedshearstress:分切应Anappliedtensileorcompressivestressresolvedintoashearcomponentalongaspecificneanddirectionwithinthatne.Slip:滑sticdeformationastheresultofdislocationmotion;also,thesheardiscementoftwoadjacentnesofatoms.Slipsystem:滑移Thecombinationofacrystallographicneand,withinthatne,acrystallographicdirectionalongwhichslip(i.e.,dislocationmotion)occurs.Solid-solutionstrengthening:固溶强化Hardeningandstrengtheningofmetalsthatresultfromalloyinginwhichasolidsolutionisformed.ThepresenceofimpurityatomsrestrictsdislocationStrainhardening:Theincreaseinhardnessandstrengthofaductilemetalasitissticallydeformedbelowitsrecrystallizationtemperature.

Viscosity):粘Theratioofthemagnitudeofanappliedshearstresstothevelocitygradientthatitproduces;thatis,ameasureofanoncrystallinematerial’s permanentdeformation.Vulcanization:硫Nonreversiblechemicalreactioninvolvingsulfurorothersuitableagentwhereincrosslinksareformedbetweenmolecularchainsinrubbermaterials.过发生的不可逆化学反应。此种反应在橡胶Foreachofedge,screw,andmixeddislocations,citetherelationshipbetweenthedirectionoftheappliedshearstressandthedirectionofdislocationlinemotion.(a)DefineaslipDoallmetalshavethesameslipsystem?Whyorwhynot?8.8OneslipsystemfortheHCPcrystalstructure{000}<1120>.InamannersimilartoFigure8.6b,sketcha{000}-typenefortheHCPstructure,andusingarrows,indicatethreedifferent<1120>slipdirectionswithinthisne.YoumightfindFigure3.22helpful.能，可以进行材料生产过的故障分析，还可1、()画简单的完全固溶相图和共晶相图的()存在的相()(b)写出加热或冷却时上述所有转变的反4、已知组成在0.022wtC和2.14wtC之()指定合金是否为亚共析或过共析合金Austenite:Fe所形成的间隙固溶体。Cementite:Fe3C叫做渗碳体，它的含碳量为6.67%Component:组成合金的化学组分(元素或化合物)，可用于确

其组成Congruenttransformation:无成分变化转变EquilibriumPhase):平衡(相Eutecticstructure:织)。Eutecticphase:Eutecticreaction:Eutectoidreaction:Ferrite:energy:Gibbsphaserule:相Hypereutectoidalloy:Hypoeutectoidalloy:Intermediatesolidsolution:中间固溶体Intermetalliccompound:Invariantpoint:Isomorphous:Leverrule:Liquidusline:Metastable:Microconstituent:Pearlite:Peritecticreaction:

Phase:Phasediagram:Primaryphase:Proeutectoidcementite:Proeutectoidferrite:Solidusline:Solubilitylimit:Solvusline:System:(2)Terminalsolidsolution:Tieline:10.11A1.5kgspecimenofa90wt%Pb-10wt%Snalloyisheatedto250C,atwhichtemperatureisentirelyanphasesolidsolution(Figure10.7).Thealloyistobemeltedtotheextentthat50%of

thespecimenisliquid,theremainderbeingphase.Thismaybe plishedeitherbyheatingthealloyorchangingitscompositionwhileholdingthetemperatureconstant.Towhattemperaturemustthespecimenbeheated?TheSpecimenmustbeheatedto295.84C.Howmuchtinmustbeaddedtothespecimenat250Ctoachievethis答(a)样品必须加热到(b)此时的组成应为23.7wtSn。设加入的Sn量为xkg，则应满足下列关系。Wx1.5W

当合金组成为30wt%A70wt%B时，同理有即相的组成为10.27组成为55wtB45wtA的A-B合金，在相组成。如果90wt%B10设相的组成为xwtB,(55-x)W=(90-55) 1.5

10.24A30wt%Sn70wt%Pballoyisheatedtoatemperaturewithinthe+liquidphaseregion.Ifthemassfractionofeachphaseis0.5,estimate(a)thetemperatureofthealloy,and(b)thecompositionsofthetwophases.答：(a)根据SnPb相图，组成为A30wt%Sn70的对应合金温度为225C。平衡两相中，相的组成为16.4wt%Sn83.6wt%Pb，液相的组成为43.6wt%Sn56.4wt%Pb。

10.51相和组织的区别是什么？10.69组成5wt%C95wt%FeFeC合金，答：1175C时：L+Fe3C；1145C时：+Fe3C；700C时：+Fe3C示意草图（略第十一章相10.26ABA的相和富含B的平衡两相组成，合金成 相分相分 相的组成为xwtB相的组成为ywtB，

要。例如，共析组成(0.76wtC)Fe-C合金，700MPa2000MPa之间变化。体，粗状珠光体，球状体，贝氏体，马氏体4、根据某些Fe-C合金的等温转变(或连续冷却转Alloysteel:含有显著的合金元素(除了C和残余的MnSiS和Artificialaging:Athermaltransformation:Bainite:Coarsepearlite:铁素体和渗碳体交替的层距相对厚的珠光ContinuouscoolingtransformationFinepearlite:

铁素体和渗碳体交替的层距相对薄的珠光Glasstransitiontemperature:Isothermaltransformationdiagram(T-T-T):等温Kinetics:Martensite:Naturalaging:Nucleation:Overaging:沉淀硬化过，超过最大的强度和硬度点的时Phasetransformation:incarbonsteel:普通碳钢Precipitationhardening:Precipitationheattreatment:沉淀硬化处理，人Solutionheattreatment:Spheroidite:Supercooling:Superheating:Temperedmartensite:Thermallyactivatedtransformation:热激活转变于温度，其定量关系见11.3。Transformationrate:反应进行至一半时所需的时间的倒数11.5奥氏体马氏体转变动力学服从Avrami方95%的奥氏体转变为珠光体所需的总的时Fraction 答：Avramiy代入数据：y1=0.2,t1=12.6：求得：代入数据：y2=0.8t2=28.2，求得：接着代入y3=0.95,n=2.45，k=4.4910-4，求得t3=35s35秒第十二章在部件或者结构的设计过，材料电学性

描述固体材料中4种可能的电子能带结构给定电荷的载流子浓度和迁移率，计算金对于p-n结，根据其子与空穴的运动来解释其整流过程。Acceptorstate:Whenimpurityatomswithavalenceof3isaddedasasubstitutionalimpurityintosiliconcrystal,oneofthecovalentbondsaroundeachoftheseatomsisdeficientinanelectron;suchadeficiencymaybeviewedasaholethatisweaklyboundtotheimpurityatom.Eachimpurityatomofthistypeintroducesanenergylevelwithinthebandgap,aboveyetveryclosetothetopofthevalencebandwhichistermedacceptorstate.Conductionband:Inbandstructures,onebandthatisemptywithelectronsistermedconductionband.Electricalconductivityσisthereciprocaloftheresistivity,orσ=1/ρandisindicativeoftheeasewithwhichamaterialiscapableofconductinganelectriccurrent.电导率σ是电阻率的倒数，或者σ=1/ρDonorstate:Whenanimpurityatomwithavalenceof5isaddedasasubstitutionalimpurityintosiliconcrystal,only4of5valenceelectronsofthisimpurityatomcanparticipateinthebondingandtheextranonbondingelectronislooselyboundtotheregionaroundtheimpurityatom.Foreachofsuchlooselybondelectrons,thereexistsasingleenergylevel,orenergystate,whichislocatedwithintheforbiddenbandgapjustbelowthebottomoftheconduc