Dislocation dynamics during plastic deformation

509 Pages·2010·6.989 MB·English

by  Ulrich Messerschmidt

SpringerSeriesin
materials science
129
SpringerSeriesin
materials science
Editors: R.Hull C.Jagadish R.M.Osgood,Jr. J.Parisi Z.Wang H.Warlimont
The Springer Series in Materials Science covers the complete spectrum of materials physics,
includingfundamentalprinciples,physicalproperties,materialstheoryanddesign.Recognizing
theincreasingimportanceofmaterialsscienceinfuturedevicetechnologies,thebooktitlesinthis
seriesreflectthestate-of-the-artinunderstandingandcontrollingthestructureandproperties
ofallimportantclassesofmaterials.
PleaseviewavailabletitlesinSpringerSeriesinMaterialsScience
onserieshomepagehttp://www.springer.com/series/856
Ulrich Messerschmidt
Dislocation Dynamics
During Plastic Deformation
With291 Figures and 56 Video Sequences
123
ProfessorDr.UlrichMesserschmidt
GuestScientistatMaxPlanckInstituteofMicrostructurePhysics
Weinberg2,06120Halle(Saale),Germany
E-mail:[email protected]
SeriesEditors:
ProfessorRobertHull ProfessorJu¨rgenParisi
UniversityofVirginia Universita¨tOldenburg,FachbereichPhysik
Dept.ofMaterialsScienceandEngineering Abt.Energie-undHalbleiterforschung
ThorntonHall Carl-von-Ossietzky-Straße9–11
Charlottesville,VA22903-2442,USA 26129Oldenburg,Germany
ProfessorChennupatiJagadish Dr.ZhimingWang
AustralianNationalUniversity UniversityofArkansas
ResearchSchoolofPhysicsandEngineering DepartmentofPhysics
J4-22,CarverBuilding 835W.DicknsonSt.
CanberraACT0200,Australia Fayetteville,AR72701,USA
ProfessorR.M.Osgood,Jr. ProfessorHansWarlimont
MicroelectronicsScienceLaboratory DSLDresdenMaterial-InnovationGmbH
DepartmentofElectricalEngineering PirnaerLandstr.176
ColumbiaUniversity 01257Dresden,Germany
SeeleyW.MuddBuilding
NewYork,NY10027,USA
Additional materialto thisbook (video clips of dislocation motion) canbe
downloaded from h ttp://extras.springer.com/2010/978-3-642-03176-2
SpringerSeriesinMaterialsScience ISSN0933-033X
ISBN978-3-642-03176-2 e-ISBN978-3-642-03177-9
DOI10.1007/978-3-642-03177-9
SpringerHeidelbergDordrechtLondonNewYork
LibraryofCongressControl Number: 2009938024
©Springer-VerlagBerlinHeidelberg2010
This work is subject to copyright. All rights are reserved, whether the whole or part of the material is
concerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation,broadcasting,
reproductiononmicrofilmorinanyotherway,andstorageindatabanks.Duplicationofthispublicationor
partsthereofispermittedonlyundertheprovisionsoftheGermanCopyrightLawofSeptember9,1965,inits
currentversion,andpermissionforusemustalwaysbeobtainedfromSpringer-Verlag.Violationsareliable
toprosecutionundertheGermanCopyrightLaw.
Theuseofgeneraldescriptivenames,registerednames,trademarks,etc.inthispublicationdoesnotimply,
evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevantprotectivelawsand
regulationsandthereforefreeforgeneraluse.
Cover design:eStudio Calamar Steinen
Printedonacid-freepaper
SpringerisapartofSpringerScience+BusinessMedia(www.springer.com)
Preface
Very many structural materials like metals and ceramics are of crystalline
nature.Undermostoftheconditions,theyundergoplasticdeformationbefore
they fail under load. The plastic deformation is mediated by the genera-
tionandmotionofone-dimensionalcrystaldefects,the so-calleddislocations.
Thus, the density and dynamic properties of the dislocations determine the
plastic behavior of the respective materials and frequently also their failure.
Thedislocationdynamics,thatis,theresponseofthedislocationstoanexter-
nal load, is controlled by the interaction between the moving dislocations
with the periodic crystal lattice structure, other crystal defects from point
defectsoversmallclusterstolargerprecipitates,withotherdislocationsform-
ing a microstructure through which the mobile dislocations have to move,
and finally the grain and phase structure of the material. Considering these
different interactions,the dislocation motion turns out to be quite a complex
process.
In situ straining experiments in a transmission electron microscope are
a powerful means for studying the microprocesses controlling the dislocation
mobility.Withthismethod,dislocationscandirectlybeobservedduringtheir
motionunderload.Thetechniqueadvancedwhenhigh-voltageelectronmicro-
scopes became commercially available at the end of the 1960s, first in Japan
and later on also in other countries. These microscopes enable the transmis-
sion of thicker specimens, which have properties similar to macroscopic bulk
specimens.Besides,theyoffersufficientroomforelaboratedeformationstages
in the specimen chamber. In the last 30 years, in situ straining experiments
were performed on many materials, both in conventional and in high-voltage
electron microscopes. The present author and his coworkers performed such
experiments over about 30 years, yielding many hours of video recordings of
dislocation motion.
This book gives an introduction into the processes controlling the dislo-
cation dynamics and its role in crystal plasticity. It is divided into two parts.
PartIdescribesthegeneralpropertiesofdislocationmotioninanintroductory
waysuitedalsoforstudentswithoutpriorknowledgeindislocationproperties.
VI Preface
“Dislocations” in a mowed lawn (solarized)
It is based on lectures given in the Physics Department of the Martin
Luther University in Halle (Saale). For easy understanding, the mathe-
matical treatment is presented on a simple level. In Part II, particular
materialsarediscussedcoveringsemiconductors,ceramicsinglecrystals,met-
als, and alloys including intermetallic alloys and quasicrystals. The whole
text is, whenever possible, illustrated by electron micrographs, partly of
dislocations under load taken during in situ straining experiments in a high-
voltage electron microscope. Besides, video files can be downloaded from
http://extras.springer.com/2010/978-3-642-03176-2 presenting characteristic
video sequences of moving dislocations. The videos are commented in the
chapters of Part II but are referred to also in Part I. The presentation of
the differentmaterialsisnotexhaustivebutintendedto explaintheprocesses
showninthevideos.Itisamainaimofthisworktomakethevideosequences
available to a greater number of scientists and lecturers.
The experimental work frequently referred to in this book and exploited
for the video clips was carried out in the Institute of Solid State Physics and
ElectronMicroscopyof the Academy of Sciences of the GDR in Halle (Saale)
and since 1992 in the Max Planck Institute of Microstructure Physics at the
same place. The author is very grateful to all responsible directors, that is,
thelateHeinzBethge,VolkerSchmidt,andJu¨rgenKirschner,forcreatingthe
experimentalandcollaborativeenvironmentforthesestudies.Thecontinuous
high-quality performance of the high-voltage electron microscope was essen-
tially due to Christian Dietzsch. The author acknowledges the contributions
Preface VII
of many scientists to the experiments and interpretations; first of all to Fritz
Appel for the work on NaCl, MgO, and some metals, and Martin Bartsch
for the studies on all other materials. He had an essential influence on the
experiments and the instruction of the PhD students and post-doctoral fel-
lowswho workedin projectsfunded by the Deutsche Forschungsgemeinschaft
and the Volkswagenstiftung. He also saved the original video recordings in
digitalformandhelped tocollectdataforthe book,andhe discussedits con-
tents.Manyotherscientistswereinvolvedintheexperiments.Theirnamesare
listed below.1 Ju¨rgen Kirschner supported the preparation of the book after
myretirement.Hans-RainerTrebin,BorisV.Petukhov,WolfgangBlum,Hart-
mut Leipner, and Ichiro Yonenaga discussed special topics or helped finding
suitable references. Video clips were made available by Daniel Caillard and
Volker Mohles. The author is very grateful for all these contributions. The
English of the text was kindly revised by Heike Messerschmidt.
Halle (Saale) Ulrich Messerschmidt
December 2009
1 Part of the experimental work was carried out by the PhD students and post-
doctoral fellows Susanne Guder, Anna Wasilkowska, Dietmar Baither, Bernd
Baufeld, Ralf Hausha¨lter, Dietrich Ha¨ussler, Bert Geyer, Ludwig Junker, Lars
Ledig, and Aleksander Tikhonovski. Several studies were performed in close
collaboration with other laboratories. In this respect, I thank the late Peter
Haasen, Manfred Ru¨hle, Knut Urban, Toru Imura, Masaharu Yamaguchi, Eck-
hardNembach,BerndReppich,GerhardSauthoff,EduardM.Nadgornyi,PeterJ.
Wilbrandt,MarkusWollgarten,MichaelFeuerbacher,PeterSchall,MarkAindow,
Ian Jones, Hiro Saka, Yoichi Nishino, Christina Scheu, Easo P. George, Witold
Zielinski, and Michael Mills. Furthernames will be found in thereferences.
Contents
Part I General Properties of Dislocation Motion
1 Introduction............................................... 3
1.1 Theoretical Yield Strength................................ 4
1.2 Plastic Shear by the Motion of Dislocations................. 5
2 Experimental Methods .................................... 11
2.1 Macroscopic Deformation Tests ........................... 11
2.2 Stress Pulse Double Etching Technique..................... 16
2.3 Transmission Electron Microscopy ......................... 18
2.4 In Situ Straining Experiments in the Transmission Electron
Microscope ............................................. 20
2.5 Other Methods.......................................... 26
2.5.1 X-Ray Topography In Situ Deformation Experiments .. 27
2.5.2 Surface Studies of Slip Lines ........................ 27
2.5.3 Internal Friction................................... 29
2.5.4 Nuclear Magnetic Resonance........................ 33
3 Properties of Dislocations ................................. 35
3.1 Geometric Properties .................................... 35
3.1.1 Burgers Vector.................................... 35
3.1.2 Glide and Climb Motion of a Dislocation ............. 37
3.1.3 Relation Between Dislocation Motion
and Plastic Strain and Strain Rate .................. 39
3.2 Elastic Properties of Dislocations.......................... 40
3.2.1 Stress Fields of Straight Dislocations................. 41
3.2.2 Dislocation Energy ................................ 43
3.2.3 Forces on Dislocations ............................. 47
3.2.4 Interaction Between ParallelDislocations............. 50
3.2.5 Interaction Between Nonparallel Dislocations ......... 52
X Contents
3.2.6 Elastic Interaction Between Dislocations
and Elastic Inclusions.............................. 54
3.2.7 Bowed-Out Dislocations............................ 57
3.3 Dislocations in Crystals .................................. 65
3.3.1 Selection of Burgers Vectors ........................ 66
3.3.2 Stacking Faults and Partial Dislocations.............. 66
3.3.3 Twins............................................ 70
3.3.4 Antiphase Boundaries.............................. 71
4 Dislocation Motion ........................................ 73
4.1 Thermally Activated Overcoming of Barriers................ 74
4.2 Lattice Friction ......................................... 78
4.2.1 Peierls–NabarroModel............................. 79
4.2.2 Double-Kink Model................................ 83
4.2.3 Characteristics and Experimental Evidence
of the Double-Kink Model .......................... 92
4.3 Slip and Cross Slip ...................................... 93
4.4 The Locking–Unlocking Mechanism........................ 99
4.5 Overcoming of Localized Obstacles ........................101
4.5.1 Friedel Statistics ..................................103
4.5.2 Mott Statistics....................................110
4.6 Transition from the Double-Kink Mechanism
to the Overcoming of Localized Obstacles ..................113
4.7 Overcoming of Extended Obstacles ........................116
4.8 Dislocation Intersections .................................126
4.9 Dislocation Motion at High Velocities
and Low Temperatures...................................129
4.10 Dislocation Climb .......................................132
4.10.1 Point Defect Equilibrium Concentrations .............132
4.10.2 Climb Forces .....................................134
4.10.3 Emission- or Absorption-controlledClimb ............137
4.10.4 Diffusion-controlled Climb..........................140
4.10.5 Jog Dragging .....................................141
4.11 Drag Forces due to Point Defect Atmospheres...............143
4.12 Dynamic Laws of Dislocation Mobility .....................150
5 Dislocation Kinetics, Work-Hardening, and Recovery ......155
5.1 Dislocation Kinetics .....................................155
5.1.1 Models of Dislocation Generation....................156
5.1.2 Experimental Evidence of Dislocation Generation......162
5.1.3 Dislocation Immobilization and Annihilation..........166
5.2 Work-Hardening and Recovery ............................171
5.2.1 Work-Hardening Models............................172
5.2.2 Thermal and Athermal Components
of the Flow Stress .................................180