材料科学基础英文版习题.docx

材料科学基础英文版习题.docx

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材料科学基础英文版习题

Chapter6,Problem1

Whyarecastmetalsheetingotshot-rolledfirstinsteadofbeingcold-rolled?

Chapter6,Problem2

Whattypeofheattreatmentisgiventotherolledmetalsheetafterhotand“warm”rolling?

Whatisitspurpose?

Chapter6，Problem3

（a）Howaremetalalloysmadebythecastingprocess?

（b）Distinguishbetweenwroughtalloyproductsandcastalloyproducts.

Chapter6,Problem4

Describethewire-drawingprocess.Whyisitnecessarytomakesurethesurfaceoftheincomingwireiscleanandlubricated?

Chapter6,Problem5

Describeandillustratethefollowingtypesofextrusionprocesses:

（a）directextrusionand（b）indirectextrusion.Whatisanadvantageofeachprocess?

Chapter6,Problem6

Describetheforgingprocess.Whatisthedifferencebetweenhammerandpressforging?

Chapter6,Problem7

Whatisthedifferencebetweenopen-dieandclosed-dieforging?

Illustrate.Giveanexampleofametalproductproducedbyeachprocess.

Chapter6,Problem8

Distinguishbetweenelasticandplasticdeformation（useschematics）.

Chapter6,Problem9

Define（a）engineeringstressandstrain,and（b）truestressandstrain,（c）WhataretheU.S.customaryandSIunitsforstressandstrain?

（d）Distinguishbetweentensile/compressivestress（alsocallednormalstress）andshearstress,（e）Distinguishbetweentensile/compressivestrain（alsocallednormalstrain）andshearstrain.

Chapter6,Problem10

（a）Definethehardnessofametal,（b）Howisthehardnessofamaterialdeterminedbyahardnesstestingmachine?

Chapter6,Problem11

Whataretheloadusedin（a）RockwellBhardnesstest,and（b）RockwellChardnesstest?

Chapter6,Problem12

WhatisthedifferencebetweenVickersandKnoophardnesstests?

Chapter6,Problem13

Describetheslipmechanismthatenablesametaltobeplasticallydeformedwithoutfracture.

Chapter6,Problem14

（a）Whydoesslipinmetalsusuallytakeplaceonthedensest-packedplanes?

（b）Whydoesslipinmetalsusuallytakeplaceintheclosest-packeddirections?

Chapter6，Problem15

（a）WhataretheprincipalslipplanesandslipdirectionsforFCCmetals?

（b）WhataretheprincipalslipplanesandslipdirectionsforBCCmetals?

（c）WhataretheprincipalslipplanesandslipdirectionsforHCPmetals?

Chapter6,Problem16

Describethedeformationtwinningprocessthatoccursinsomemetalswhentheyareplasticallydeformed.

Chapter6,Problem17

Whatisthedifferencebetweentheslipandtwinningmechanismsofplasticdeformationofmetals?

Chapter6，Problem18

WhatothertypesofslipplanesareimportantotherthanthebasalplanesforHCPmetalswithlowc/aratios?

Chapter6，Problem19

Whatimportantroledoestwinningplayintheplasticdeformationofmetalswithregardtodeformationofmetalsbyslip?

Chapter6,Problem20

Definethecriticalresolvedshearstressforapuremetalsinglecrystal?

Whathappenstothemetalfromthemacroscalepointofviewandbehaviorpointofviewoncecriticalresolvedshearstressisexceeded?

Chapter6,Problem21

Bywhatmechanismdograinboundariesstrengthenmetals?

Chapter6,Problem22

（a）Whatissolid-solutionstrengthening?

Describethetwomaintypes,（b）Whataretwoimportantfactorsthataffectsolid-solutionhardening?

Chapter6,Problem23

Whatexperimentalevidenceshowsthatgrainboundariesarrestslipinpolycrystallinemetals?

Chapter6，Problem24

（a）Describethegrainshapechangesthatoccurwhenasheetofalloyedcopperwithanoriginalequiaxedgrainstructureiscold-rolledwith30and50percentcoldreductions,（b）Whathappenstodiedislocationsubstructure?

Chapter6,Problem25

Howistheductilityofametalnormallyaffectedbycoldworking?

Why?

Chapter6,Problem26

Whatarethethreemainmetallurgicalstagesthatasheetofcold-workedmetalsuchasaluminumorcoppergoesthroughasitisheatedfromroomtemperaturetoanelevatedtemperaturejustbelowitsmeltingpoint?

Chapter6,Problem27

Whenacold-workedmetalisheatedintothetenperaturerangewhererecrystallizationtakesplace,howarethefollowingaffected:

（a）internalresidualstresses,（6）strength,（c）ductility,and（d）hardness?

Chapter6，Problem28

Whenacold-workedmetalisheatedintothetemperaturerangewhererecoverytakesplace,howarethefollowingaffected:

（a）internalresidualstresses,（b）strength,（c）ductility,and（d）hardness?

Chapter6,Problem29

Describethemicrostructureofaheavilycold-workedmetalofanAl-0.8%Mgalloyasobservedwithanopticalmicroscopeatl00x（seeFig.6.46a）.Describethemicrostructureofthesamematerialat20,000x（seeFig.6.47a）

Chapter6，Problem30

Describewhatoccursmicroscopicallywhenacold-workedsheetofmetalsuchasaluminumundergoesarecoveryheattreatment.

Chapter6,Problem31

Describewhatoccursmicroscopicallywhenacold-workedsheetofmetalsuchasaluminumundergoesarecrystallizationheattreatment.

Chapter6,Problem32

Whatgeneralizationscanbemadeabouttherecrystallizationtemperaturewithrespectto（a）thedegreeofdeformation,（b）thetemperature,（c）thetimeofheatingattemperature,{d）thefinalgrainsize,and（e）thepurityofthemetal?

Chapter6,Problem33

Describetwoprincipalmechanismswherebyprimaryrecrystallizationcanoccur.

Chapter6,Problem34

Whatarefiveimportantfactorsthataffecttherecrystallizationprocessinmetals?

Chapter6,Problem35

Definesuperplasticityandlisttheconditionsunderwhichsuperplasticitycanbeachieved.Whyisthisanimportantbehavior?

Chapter6,Problem36

Discussthemajordeformationmechanismthatresultsinextensiveplasticdeformationinsuperplasticity.

Chapter6,Problem37

Whyarenanocrystallinematerialsstronger?

Answerbasedondislocationactivity.

Chapter6,Problem38

A70%Cu-30%Znbrasssheetis0.12cmthickandiscold-rolledwitha20percentreductioninthickness.Whatmustbethefinalthicknessofthesheet?

Chapter6,Problem39

A12.8-mm-diameterrodofanaluminumalloyispulledtofailureinatensiontest.Ifthefinaldiameteroftherodatthefracturedsurfaceis10.8mm,whatisthepercentreductioninareaofthesampleduetothetest?

Chapter6,Problem40

Calculatethepercentcoldreductionwhenanaluminumwireiscold-drawnfromadiameterof6.50mmtoadiameterof4.25mm.

Chapter6,Problem41

Whatistherelationshipbetweenengineeringstrainandpercentelongation?

Chapter6,Problem42

Asheetofaluminumalloyiscold-rolled25percenttoathicknessof0.2cm.Ifthesheetisthencold-rolledtoafinalthicknessof0.16cm,whatisthetotalpercentcoldworkdone?

Chapter6,Problem43

Atensilespecimenofcartridgebrasssheethasacrosssectionof10.0mmx4.0mmandagagelengthof51mm.Calculatetheengineeringstrainthatoccurredduringatestifthedistancebetweengagemarkingsis63mmafterthetest.

Chapter6,Problem44

Abrasswireiscold-drawn30percenttoadiameterof0.90mm.Itisthenfurthercold-drawnto0.70mm.Whatisthetotalpercentcoldreduction?

Chapter6,Problem45

Thefollowingengineeringstress-straindatawereobtainedforametal,（a）Plottheengineeringstress-straincurve,（b）Determinetheultimatetensilestrengthofthealloy,（c）Determinethepercentelongationatfracture.

Engineering

stress

（MPa）

Engineering

strain

（mm/mm）

Engineering

stress

（MPa）

Engineering

strain

（mm/mm）

0

0

76

0.08

30

0.001

75

0.10

55

0.002

73

0.12

60

0.005

69

0.14

68

0.01

65

0.16

72

0.02

56

0.18

74

0.04

51

（Fracture）0.19

75

0.06

Chapter6，Problem46

FromthedataofProb.6.45,estimatetheyieldstrengthofthemetal.

Chapter6,Problem47

Thefollowingengineeringstress-straindatawereobtainedatthebeginningofatensiletestforametal,（a）Plottheengineeringstress-straincurveforthesedata.（b）Determinethe0.2percentoffsetyieldstressforthissteel,（c）Determinethetensileelasticmodulusofthissteel.（Notethatthesedataonlygivethebeginningpartofthestress-straincurve.）

Engineering

stress

（MPa）

Engineering

strain

（mm/mm）

Engineering

stress

（MPa）

Engineering

strain

（mm/mm）

0

0

60

0.0035

15

0.0005

66

0.004

30

0.001

70

0.006

40

0.0015

72

0.008

50

0.0020

Chapter6,Problem48

Thefollowingengineeringstress-straindatawereobtainedatthebeginningofatensiletestfora0.2%Cplaincarbonsteel,（a）Plottheengineeringstress-straincurveforthesedata,（b）Determinethe0.2percentoffsetyieldstressforthissteel,（c）Determinethetensileelasticmodulusofthissteel.（Notethatthesedataonlygivethebeginningpartofthestress-straincurve.）

Engineering

Engineering

Engineering

Engineering

Stress

Strain

Stress

Strain

（MPa）

（mm/mm）

（MPa）

（mm/mm）

0

0

413.4

0.0035

103.4

0.0005

454.7

0.0040

206.7

0.0010

482.3

0.0060

275.6

0.0015

496.1

0.0080

344.5

0.0020

Chapter6,Problem49

Atensilespecimenofaluminumalloyistestedtofracture.Atthefracturepoint,ithasanengineeringstress180MPaandengineeringstrain34%.Calculate（a）thetruestressatfracture,and（b）thetruestrainatfracture.

Chapter6,Problem50

Astressof55MPaisappliedinthe[001]directionofaBCCsinglecrystal.Calculate（a）theresolvedshearstressactingonthe（101）

systemand（b）theresolvedshearstressactingonthe（110）

system.

Chapter6,Problem51

Astressof4.75MPaisappliedinthe

directionofaunitcellofanFCCcoppersinglecrystal.Calculatetheresolvedshearstressonthe

planeinthefollowingdirections:

（a）

（b）

（c）

Chapter6,Problem52

A20-cm-longrodwithadiameterof0.250cmisloadedwitha5000Nweight.Ifthediamet