Fundamentals of Friction and Wear

712 Pages·2007·23.309 MB·English

by  Roland Bennewitz (auth.), Dr. Enrico Gnecco, Professor Dr. Ernst Meyer (eds.)

NanoScience and Technology
NanoScience and Technology
SeriesEditors:
P.Avouris B.Bhushan D.Bimberg K.vonKlitzing H.Sakaki R.Wiesendanger
The series NanoScience and Technology is focused on the fascinating nano-world,
mesoscopicphysics,analysiswithatomicresolution,nanoandquantum-effectdevices,
nanomechanics and atomic-scale processes. All the basic aspects and technology-
orienteddevelopmentsinthisemergingdisciplinearecoveredbycomprehensiveand
timelybooks.Theseriesconstitutesasurveyoftherelevantspecialtopics,whichare
presentedbyleadingexpertsinthefield.Thesebookswillappealtoresearchers,engi-
neers,andadvancedstudents.
AppliedScanningProbeMethodsI AppliedScanningProbeMethodsII
Editors:B.Bhushan,H.Fuchs,and ScanningProbeMicroscopy
S.Hosaka Techniques
Editors:B.Bhushan,H.Fuchs
Nanostructures
TheoryandModeling
AppliedScanningProbeMethodsIII
ByC.DelerueandM.Lannoo
Characterization
NanoscaleCharacterisation Editors:B.Bhushan,H.Fuchs
ofFerroelectricMaterials
AppliedScanningProbeMethodsIV
ScanningProbeMicroscopyApproach
IndustrialApplication
Editors:M.AlexeandA.Gruverman
Editors:B.Bhushan,H.Fuchs
MagneticMicroscopy
ofNanostructures Nanocatalysis
Editors:H.HopsterandH.P.Oepen Editors:U.Heiz,U.Landman
SiliconQuantumIntegratedCircuits
Roadmap
Silicon-GermaniumHeterostructure
ofScanningProbeMicroscopy
Devices:BasicsandRealisations
Editors:S.Morita
ByE.Kasper,D.J.Paul
Nanostructures–
ThePhysicsofNanotubes
FabricationandAnalysis
FundamentalsofTheory,Optics
Editor:H.Nejo
andTransportDevices
Editors:S.V.RotkinandS.Subramoney
AppliedScanningProbeMethodsV
SingleMoleculeChemistry ScanningProbeMicroscopyTechniques
andPhysics Editors:B.Bhushan,H.Fuchs,
AnIntroduction S.Kawata
ByC.Wang,C.Bai
AppliedScanningProbeMethodsVI
AtomicForceMicroscopy,Scanning
Characterization
NearfieldOpticalMicroscopy
Editors:B.Bhushan,S.Kawata
andNanoscratching
ApplicationtoRough AppliedScanningProbeMethodsVII
andNaturalSurfaces BiomimeticsandIndustrialApplications
ByG.Kaupp Editors:B.Bhushan,H.Fuchs
Enrico Gnecco
Ernst Meyer
Fundamentals
of Friction
and Wear
With300Figuresand13Tables
123
Editors:
Dr.EnricoGnecco ProfessorDr.ErnstMeyer
UniversitätBasel UniversitätBasel
InstitutfürPhysik InstitutfürPhysik
Klingelbergstr.82,4056Basel,Switzerland Klingelbergstr.82,4056Basel,Switzerland
e-mail:[email protected] e-mail:[email protected]
SeriesEditors:
ProfessorDr.PhaedonAvouris ProfessorDr.,Dres.h.c.
IBMResearchDivision KlausvonKlitzing
NanometerScaleScience&Technology Max-Planck-InstitutfürFestkörperforschung
ThomasJ.WatsonResearchCenter,P.O.Box218 Heisenbergstrasse1,70569Stuttgart,Germany
YorktownHeights,NY10598,USA
ProfessorHiroyukiSakaki
ProfessorBharatBhushan UniversityofTokyo
NanotribologyLaboratoryforInformation InstituteofIndustrialScience,
StorageandMEMS/NEMS(NLIM) 4-6-1Komaba,Meguro-ku,Tokyo153-8505,Japan
W390ScottLaboratory,201W.19thAvenue
ProfessorDr.RolandWiesendanger
TheOhioStateUniversity,Columbus
InstitutfürAngewandtePhysik
Ohio43210-1142,USA
UniversitätHamburg
ProfessorDr.DieterBimberg Jungiusstrasse11,20355Hamburg,Germany
TUBerlin,FakutätMathematik,
Naturwissenschaften,
InstitutfürFestkörperphysik
Hardenbergstr.36,10623Berlin,Germany
ISBN-10 3-540-36806-X SpringerBerlinHeidelbergNewYork
ISBN-13 978-3-540-36806-9 SpringerBerlinHeidelbergNewYork
LibraryofCongressControlNumber:2006934355
Thisworkissubjecttocopyright.Allrightsarereserved,whetherthewholeorpartofthematerialisconcerned,
specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation,broadcasting,reproductionon
microfilmorinanyotherway,andstorageindatabanks.Duplicationofthispublicationorpartsthereofispermitted
onlyundertheprovisionsoftheGermanCopyrightLawofSeptember9,1965,initscurrentversion,andpermission
forusemustalwaysbeobtainedfromSpringer.ViolationsareliableforprosecutionundertheGermanCopyright
Law.
SpringerisapartofSpringerScience+BusinessMedia
springer.com
©Springer-VerlagBerlinHeidelberg2007
Theuseofgeneraldescriptivenames,registerednames,trademarks,etc.inthispublicationdoesnotimply,evenin
theabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevantprotectivelawsandregulationsand
thereforefreeforgeneraluse.
Productliability:Thepublisherscannotguaranteetheaccuracyofanyinformationaboutdosageandapplication
containedinthisbook.Ineveryindividualcasetheusermustchecksuchinformationbyconsultingtherelevant
literature.
Typesetting:LE-TEXJelonek,Schmidt&VöcklerGbR,Leipzig
Production:LE-TEXJelonek,Schmidt&VöcklerGbR,Leipzig
Cover:WMXDesign,Heidelberg
SPIN11555315 57/3100/YL-543210 Printedonacid-freepaper
Preface
Friction is an old subject of research and is certainly one of the most im-
portant ones from a practical point of view. The da Vinci-Amonton laws
are common knowledge (1. Friction is independent of apparentcontact area,
2. Friction is proportional to the normal load 3. Friction is independent of
velocity). Experiments with small contacts have shown that these empiri-
cal laws of friction do not always hold. Reasons may be related to the large
surface-to-volumeratioandthegreaterimportanceofadhesion,surfacestruc-
ture and surface chemistry. Therefore, there is some need to get a better
understanding of the phenomenon of friction, to learn how to quantify and
eventually control it. In the first half of last century the school of Bowden
and Tabor have performed systematic, macroscopic experiments and have
related macroscopic friction to small contacting asperities. In the 1990’s ex-
periments performed with atomic force microscopy, surface force apparatus
and quartz microbalance,revealedinteresting new physics on the nanometer
scale (atomic-scale stick-slip, confinement of liquid films, determination of
electronic andphononic contributionsto dissipation).During the sametime,
theoreticalanalysisofnanometer-sizedcontactshasbeenperformedandgave
insight into the processes in the buried interface. Strong activities were pur-
sued in the US at Universities and corporate research laboratories. Similar
activities were pursued in Japan, where the main focus was on the under-
standing the tribology of hard disc drives and applications in automobile
industries. Europe has a long tradition in mechanical engineering sciences.
Activities at the University level were mainly drivenby recent developments
in nanosciences (scanning probe microscopy, computer modelling). In 2001,
the EuropeanScienceFoundationProgramme“Nanotribology”(NATRIBO)
wasstarted.Theaimofthisprogrammeistobringtogetherexperimentalists
andtheoreticianstoimprovethe understandingofnanometer-sizedcontacts.
The aim of this book is to give an overview of the status of resarch in this
field. Members of the NATRIBO-network and a selection of excellent inter-
nationalexperts havecontributedtothis book.They made a strongeffortto
give a deep insight into the complex phenomena of nanotribology.
The book is divided in seven sections. In the first section the instrumen-
tal setups most commonly used in nanotribology are introduced. The first
chapter presents the atomic force microscope (AFM), with a special empha-
sis on the force sensors and the ways to control the contact between tip and
VI Preface
surface. The interrelations between friction, load, material properties, tem-
perature, and the lateral forces detected in dynamic measurements, are also
discussed. The secondchapter introduces the surface force apparatus (SFA),
as an independent tool and in combination with other techniques. A case
study of weakly adhesive surface under shear is discussed. The quartz crys-
tal microbalance is treated in Chapt. 3. After the acoustics of the crystal,
the driving circuits and the quality of the surface electrodes, the authors
present results obtained in ultra-high vacuum (UHV). Chapter 4 describes
theeffectsofnormalandshearultrasonicvibrationsinAFM,focusinginpar-
ticular onfrictionreductionandadhesionhysteresis.Finally,Chapt.5shows
howscanningprobemicroscopescanbecombinedwithtransmissionelectron
microscopes to image both tip and sample surface. Contact formation and
breaking, adhesion effects, electric conductivity and material transport are
consequently discussed.
Section 2 gives a detailed overview on friction phenomena occurring on
the atomic scale. Chapter 6 introduces the Tomlinson model and fundamen-
tal phenomena observed by AFM (atomic stick-slip, velocity dependence of
friction, superlubricity, and nanowear processes). The next chapter shows
how the rate theory has been applied to obtain general force-velocity rela-
tions.Analyticalapproximationsarecomparedwithprecisenumericalresults.
Chapter 8 introduces the important problem of friction control. Mechanical
and chemical methods to achieve this goal are discussed from both theo-
retical and experimental points of view. Superlubricity is the main topic of
Chapts.9–11.Chapter9showshowsurfaceincommensurabilityandthermal
effects canleadtoastrongreductionoffriction,whichwasrecentlyobserved
experimentally.Lubricationbygraphite,diamond-likecarbon,fullerenesand
carbonnanotubeisdiscussedwithinthisframe.Chapter10presentstheoret-
ical studies of superlubricity. Symmetry considerations, role of instabilities,
temperature effects, damping in the superlubric regime and long-range elas-
tic deformations are discussed, as well as generic models and applications to
layeredmaterials,metal-metalcontactsandhydrogen-terminatedsurfaces.In
particular,the presenceofhydrogenis provedto be the key factorleadingto
superlubricity between diamond surfacesas shown in the detailed theoretical
study presented in the last chapter of the section.
The third section of the book introduces contact mechanics on the
nanoscale. After a brief theoretical introduction, Chapter 12 describes the
mainexperimentalmethods toinvestigateelasticityonthe nanoscaleandre-
centfindingsrelatedtoinorganicnano-objectsandbiologicalsamples.Chap-
ter 13addressesthe specialcaseonmetallicnanocontacts,whosemechanical
properties cannot be separated from electron transport mechanisms. Fabri-
cation, elasticy, fracture, and shape of metal contacts are discussed, as well
aschainsofgoldatomsandmetallicadhesioninatomic-sizedtunnelingjunc-
tions.Quasi-crystalsarethemainsubjectofChapt.14.Thisleadstheauthors
to describe the surface roughnessin relationto frictionand adhesion.A par-
Preface VII
ticular emphasis is given on the roughness power spectrum, which is derived
fromthesurfaceheightusingopticalandscanningprobemicroscopes.Chap-
ter 15 focuses on the roughness of self-affine fractal surfaces. The contact
morphology and the pressure distribution are estimated at different scales,
with and without adhesion, using molecular dynamics, and they are com-
pared with analytical contact models based on continuum mechanics. The
role of the elastic moduli of the underlying bulk is also treated here. Finally,
the last chapter of this section describes how nanoroughness is affected by
depth-sensing indentation. A special attention is given to elastomer probes
used in AFM investigations.
Section 4 describes dissipative mechanisms at finite separationunder dif-
ferentpointsofview.Chapter17dealswiththecaseofamplitudemodulation
AFM, used to characterize surfaces in air or in liquids. In such case the en-
ergy dissipation accompanying the imaging process is given by the phase
shift signal acquired while scanning. The next chapter considers dissipation
in non-contact AFM. After a review of the experimental data at our dis-
posal, possible mechanisms of atomic-scale damping are discussed, as well
as detailed models developed to understand the effect of these mechanisms
on the imaging process. The theory of non-contact friction is the subject of
Chapt. 19. The fluctuating electromagnetic field which surrounds any solid
surface,andisresponsibleforradiativeheattransferandvanderWaalsinter-
actionandfriction,isexaminedundersemiclassicalandquantumtheories.At
short separations, Van der Waals friction is greatly enhanced. Furthermore,
static charges on the surface are responsible of electrostatic friction around
amovingbody,andpossibleapplicationstoscanningprobespectroscopyare
discussed. This topic is extended in Chapt. 20, where the authors show how
the force sensitivity of free cantilevers is limited by thermal fluctuations and
material properties and how these problems are reduced by UHV annealing
or cooling to cryogenic temperatures.
Wearandfracturearetreatedinthe fifthsectionofthe book.Chapter21
covers the mechanisms of surface damage down to micro- and nano-scales.
Bothbasictheoriesandexperimentsareconsidered,andadiscussiononhard-
nessatdifferentscalesisalsoprovided.Chapter22examinesthe relationbe-
tween stress and chemical reactivity. Examples of single asperity tribochem-
ical wear include dissolution along monolayer steps in calicum carbonates
andphosphates,wearofthe probingtip onreactivesurfaces andtip induced
wear of silicate substrates. Chapter 23 gives an overview of stiction, friction
and wear phenomena affecting micro- and nano-electromechanical systems.
The tribological characterization of these devices is discussed together with
various solutions introduced to improve their reliability. The last chapter of
the section addresses nanotribological problems in automotive engineering.
Wear rates of few nanometers per hours are mandatory in internal combus-
tion engines, which requires exceptional finishing of the sliding surfaces in
the engine.
VIII Preface
Another growing field of nanotribology is the manipulation of nanoparti-
cles, which is treated in Sect. 6. Chapter 25 shows how the tip of a scanning
probemicroscopeoperatedindynamicmodecanbealternativelyusedtoim-
age and move particles in a controlled way. With a proper calibration of the
excitationamplitude the energydissipationandthe frictionalforcesinvolved
in the manipulation process can also be estimated. Chapter 26 considers
a system of great interest in nanoscience, i.e. carbon nanotubes (CNTs).
In such case AFM can be used to test mechanical properties in dynamic
and quasi-static ways.Nanotube bundles, catalyticallygrownCNTs, anddi-
ameter dependence of bending moduli are addressed as special cases. The
next chapter focuses on the manipulation of fullerene molecules on a silicon
surface. After summarizing the experimental results obtained with scanning
tunneling microscopes,the authors presenta model whichsuccessfully inter-
pretes the mechanisms underlying adsorption, diffusion and manipulation of
the molecules.
The last section of the book deals with applications of nanotribology to
organic materials. Chapter 28 gives a detailed overview of friction on self-
assembled monolayers (SAMs). Homogenoues films are first addressed, and
the influence of chain length, terminal groups, packing states as well as en-
vironmental conditions on friction are discussed. The role of nanoscale het-
erogeneitieson the nanoscaleis consideredin the secondpartofthe chapter.
The next two chapters deal with polymers. In particular, Chapt. 29 consid-
ers the influence of hydrophobicity on the frictional forces experienced on
two different materials, whereas Chapt. 30 treats the molecular origins of
elastomeric friction. Both interfacial adhesion and internal friction are ther-
mally activatedprocesses,andthe competitionbetween them givesa correct
interpretation of the experimental results. Finally, the last chapter of the
book describes the importance of friction and adhesion mechanisms in cell
dynamics, with particular emphasis on the adhesive forces experienced on
the substrates where the cells can spread and proliferate. This is of great
importance in the emerging field of tissue engineering.
Inconclusion,wewouldliketo thankallthe authorsforthe time andthe
energiesthattheyhavespentonthisproject,aswellasalltheparticipantsto
the Nanotribo workshops for the interesting scientific discussions that they
havestimulated.AspecialthanksgoesalsotoClausAscheron,AngelaLahee
andSteffiHohenseefromSpringer-Verlag,whomadepossiblethepublication
of this book. Financial support from the European Science Foundation, the
Pico-Inside project, the Swiss National Center of Competence in Research
Nanoscale Science and the Swiss National Science Foundation is gratefully
acknowledged.
University of Basel Enrico Gnecco and Ernst Meyer
Contents
Experimental Techniques
1 Friction Force Microscopy
R. Bennewitz................................................... 1
2 Surface Forces Apparatus in Nanotribology
C. Drummond, P. Richetti ....................................... 15
3 The quartz crystal microbalance
as a nanotribology technique
L. Bruschi, G. Mistura .......................................... 35
4 Nanoscale Friction and Ultrasonics
M.T. Cuberes................................................... 49
5 Probing of Nanocontacts Inside
a Transmission Electron Microscope
D. Erts, A. Lo˜hmus, J.D. Holmes, H. Olin......................... 73
Friction on the Atomic Scale, Superlubricity
6 Stick-Slip Motion on the Atomic Scale
T. Gyalog, E. Gnecco, E. Meyer .................................. 101
7 Velocity dependence of atomic friction:
Rate theory and beyond
M. Evstigneev, P. Reimann ...................................... 117
8 The Basic of Nanoscale Friction and Ways to Control it
J. Klafter, M. Urbakh ........................................... 143
9 Experimental Observations of Superlubricity
and Thermolubricity
M. Dienwiebel, J.W.M. Frenken .................................. 159
X Contents
10 Theoretical Aspects of Superlubricity
M.H. Mu¨ser.................................................... 177
11 First-Principles Atomic-Scale Study of Superlow Friction
S. Ciraci, S. Dag, O. Gulseren, T. Yildirim ........................ 201
Contact Mechanics on the Nanoscale
12 NanoMechanics: Elasticity in Nano-Objects
L. Merchan, R. Szoszkiewicz, E. Riedo............................. 219
13 Mechanical Properties
of Metallic Nanojunctions
G. Rubio-Bollinger, J.J. Riquelme, N. Agra¨ıt, S. Vieira.............. 255
14 Contact Mechanics, Friction and Adhesion
with Application to Quasicrystals
B.N.J. Persson, G. Carbone, V.N. Samoilov, I.M. Sivebaek,
U. Tartaglino, A.I. Volokitin, C. Yang............................. 269
15 A Multiscale Molecular Dynamics Approach
to Contact Mechanics and Friction: From Continuum
Mechanics to Molecular Dynamics
U. Tartaglino, C. Yang, B.N.J. Persson ........................... 307
16 The Role of Nanoroughness in Contact Mechanics
R. Buzio, U. Valbusa ............................................ 345
Dissipation Mechanisms at Finite Separations
17 Energy Dissipation and Nanoscale Imaging
in Tapping Mode AFM
R. Garc´ıa, N.F. Mart´ınez, C.J. Go´mez, A. Garc´ıa-Mart´ın............ 361
18 Mechanisms of atomic scale dissipation at close approach
in dynamic atomic force microscopy
T. Trevethan, L. Kantorovich..................................... 373
19 Theory of Noncontact Friction
A.I. Volokitin, B.N.J. Persson.................................... 393
20 Dissipation at large Separations
S. Rast, U. Gysin, E. Meyer, D.W. Lee............................ 439