Thermally Activated Mechanisms in Crystal Plasticity
|
|
- Audra Hampton
- 5 years ago
- Views:
Transcription
1 PERGAMON MATERIALS SERIES Thermally Activated Mechanisms in Crystal Plasticity by D. Caillard CEMES/CNRS-BP4347, F Toulouse Cedex J. L. Martin IPMC/EPFL-CH 1015 Lausanne 2003 PERGAMON An Imprint of Elsevier Amsterdam - Boston - London - New York - Oxford - Paris San Diego - San Francisco - Singapore - Sydney - Tokyo
2 Contents Series Preface Preface Reader's Guide v vii ix CHAPTER 1 INTRODUCTION 1.1. Scope and Outline Thermal Activation Theory: A Summary 5 References 8 CHAPTER 2 EXPERIMENTAL CHARACTERIZATION OF DISLOCATION MECHANISMS 2.1. Transient Mechanical Tests Strain-Rate Jump Experiments Stress Relaxation Tests Creep Tests Interpretation of Repeated Stress Relaxation Tests General Considerations Activation Volume and Microstructural Parameters Interpretation of Repeated Creep Tests Experimental Assessments Transition Between Monotonic and Transient Tests Examples of Repeated Creep Tests Results of Stress Relaxation Series Results of Creep Series and Comparison with Stress Relaxations Stress Reduction Experiments Conclusions About Transient Mechanical Tests Deformation Experiments in the Electron Microscope Some Key Technical Points Quantitative Information Provided by In Situ Experiments Reliability of In Situ Experiments in TEM In Situ Synchrotron X-ray Topography Observation of Slip Traces at the Specimen Surface Conclusion About the Characterization of Dislocation Mechanisms 51 References 51 xi
3 xii Contents CHAPTER 3 INTERACTIONS BETWEEN DISLOCATIONS AND SMALL-SIZE OBSTACLES 3.1. Thermally Activated Glide Across Fixed Small-size Obstacles The Rectangular Force-Distance Profile The Parabolic Force-Distance Profile The Cottrell-Bilby Potential (Cottrell and Bilby, 1949) Dislocations Interacting with Mobile Solute Atoms Long-Range Elastic Interactions Static Ageing, Dynamic Strain Ageing and the Portevin-Lechatelier Effect Diffusion-Controlled Glide Comparison with Experiments The Forest Mechanism Dislocations-Solute Atoms Interactions Domain 2: Thermally Activated Motion Across Fixed Obstacles Domain 3: Stress Instabilities and PLC Effect Domain 4: Glide Controlled by Solute-Diffusion 80 References 81 CHAPTER 4 FRICTIONAL FORCES IN METALS 4.1. Dislocation Core Structures and Peierls Potentials Kink-Pair Mechanism Principles \ Several Peierls Potentials and Associated Peierls Stresses Energy of an Isolated Kink Dorn and Rajnak Calculation (Smooth Potentials) Line Tension Approximation Abrupt Potential Energy of a Critical Bulge (High Stress Approximation) Dorn and Rajnak Calculation (1964) Line Tension Approximation Abrupt Potential Energy of a Critical Kink-Pair (Low Stress Approximation: Coulomb Elastic Interaction) Transition Between High Stress and Low Stress Regimes Properties of Dislocations Gliding by the Kink-Pair Mechanism 109
4 Contents xiii 4.3. Thermally Activated Core Transformations Transformations into a Higher Energy Core Structure Transformation into a Lower Energy Core Structure Sessile-Glissile Transformations in Series (Locking-Unlocking Mechanism) Transition Between the Locking-Unlocking and the Kink-Pair Mechanism Properties of Dislocations Gliding by the Locking-Unlocking Mechanism Conclusions 121 References 122 CHAPTER 5 DISLOCATION CROSS-SLIP 5.1. Modelling Cross-slip Elementary Mechanisms The Fleischer Model (1959) The Washburn Model (1965) The Schoeck, Seeger, Wolf model The Friedel-Escaig Cross-slip Mechanism Constriction Energy Escaig's Description of Cross-slip (1968) The Activation Energy for Cross-slip The Activation Volume Orientation Effects Refinements in the Activation Energy Estimation Experimental Assessments of Escaig's Modelling The Bonneville-Escaig Technique Experimental Observations of Cross-slip TEM Observations Optical Slip Trace Observations Peculiar Features of the Deformation Curves The Activation Parameters Experimental Study of Orientation Effects Atomistic Modelling of Dislocation Cross-slip Discussion and Conclusions Who is Closer to the Truth? Cross-slip and Stage III in FCC Metals 154 References 155
5 xiv Contents CHAPTER 6 EXPERIMENTAL STUDIES OF PEIERLS-NABARRO-TYPE FRICTION FORCES IN METALS AND ALLOYS 6.1. Prismatic Slip in HCP Metals Prismatic Slip in Titanium Prismatic Slip in Zirconium Prismatic Slip in Magnesium Prismatic Slip in Beryllium Conclusions on Prismatic Slip in HCP Metals Glide on Non-Close-Packed Planes in FCC Metals {110} Slip {100} Slip in Aluminium Creep Test Results Results of Constant Strain-Rate Tests Features of Dislocations in (001) Origin of Non-Octahedral Glide in Aluminium Glide^on Non-Close-Packed Planes in Copper Stress-Strain curves Microstructural Features Critical Stress for Non-Octahedral Glide Modelling of Non-Octahedral Glide in FCC Metals Possible Mechanisms {001} Glide in Aluminium and the Kink-Pair Mechanism Modelling {110} Glide in Aluminium Non-Octahedral Glide in Copper Comparison of FCC Metals ' The Relevance of Slip on Non-Close-Packed Planes in Close-Packed Metals Optimum Conditions for Unconventional Slip in Aluminium Non-Conventional Glide as a Rate Controlling Process Low-Temperature Plasticity of BCC Metals Mechanical Properties Iron and Iron Alloys Niobium Other BCC Metals Microstructural Observations Interpretations Conclusions on the Low-Temperature Plasticity of BCC Metals 220
6 Contents xv 6.4. The Importance of Friction Forces in Metals and Alloys 220 References 221 CHAPTER 7 THE PEIERLS-NABARRO MECHANISM IN COVALENT CRYSTALS 7.1. Dislocation Core Structures and Peierls-Nabarro Friction Forces Dislocation Velocities High Kink Mobility (Metal-Like Model of Suzuki et al., 1995) Low Kink Mobility: Case of Undissociated Dislocations Point-Obstacle Model of Celli et al. (1963) Kink Diffusion Model of Hirth and Lothe (1982) Low Kink Mobility: Case of Dissociated Dislocations Experimental Results on Dislocation Velocities Mobility as a Function of Character Elemental Semiconductors (Si) Compound Semiconductors Velocity as a Function of Stress Velocity as a Function of Temperature Regimes of Dislocation Movements Velocity Enhancement Under Irradiation Experiments at Very High Stresses Conclusions 275 References 276 CHAPTER 8 DISLOCATION CLIMB 8.1. Introduction: Basic Mechanisms ; Definition of Climb Mechanical Forces for Pure Climb Diffusion of Point Defects Jog-Point Defect Interactions Jog-Vacancy Interactions Jog-Interstitial Interactions Summary Vacancy Emission Climb Mechanism High Jog Density Climbing Dislocations with a Small Average Curvature Growth or Shrinking of Small Prismatic Dislocation Loops Low Jog Density No Pipe Diffusion 293
7 xvi Contents The Role of Pipe Diffusion Jog-Pair Nucleations Stress Dependence of the Climb Velocity Conclusion on the Vacancy-Emission Climb Mechanism Vacancy or Interstitial-Absorption Climb Mechanism High Jog Density (e.g. Curved Dislocations) Low Jog Density (e.g. Polygonal Dislocations) Growth and Shrinking of Prismatic Loops During Annealing Experimental Studies of Climb Processes Pure Climb-Plasticity Climb in HCP Magnesium and Beryllium Climb in Intermetallic Alloys Climb in Quasicrystals Growth and Shrinking of Loops During Annealing Shrinking of Vacancy Loops in Thin Foils Competitive Loop Growth in Bulk Materials Growth of Loops Under High Defect Supersaturations Conclusions on the Loop-Annealing Experiments Irradiation-Induced Creep Conclusion 318 References 318 CHAPTER 9 DISLOCATION MULTIPLICATION, EXHAUSTION AND WORK-HARDENING 9.1. Dislocation Multiplication Models of Sources i Observed Dislocation Sources Glide Sources with One Pinning Point Closed Loop Multiplication Open Loop Multiplication Multiplication Processes in Covalent Materials General Features Three Dimensional Mesoscopic Simulations of Dislocation Multiplication Testing the Proper Multiplication Laws Conclusions About Dislocation Multiplication in Covalent Crystals Mobile Dislocation Exhaustion Cell Formation 343
8 Contents xvii Exhaustion Through Lock Formation in Ni 3 Al Impurity or Solute Pinning (Cottrell Effect) Exhaustion with Annihilation Work-Hardening Versus Work-Softening Conclusions About Dislocation Multiplication, Exhaustion and Subsequent Work-Hardening Dislocation Multiplication at Surfaces Dislocation Generation at Crack Tips Dislocation Nucleation at a Solid Free Surface Conclusion on Dislocation Multiplication at Free Surfaces 358 References 358 CHAPTER 10 MECHANICAL BEHAVIOUR OF SOME ORDERED INTERMETALLIC COMPOUNDS Ni 3 Al and Ll 2 Compounds General Considerations Dislocation Cores Technical Difficulties Bound to Dislocation Core Characterization in Ni 3 Al Data About Fault Energies Cube Glide Dislocation Cores Dislocation Mobility Octahedral Glide General Considerations Microscopic Aspect of {111} Glide Complete Versus Incomplete KWL Understanding the Mechanical Properties of Ni 3 Al compounds Definition of the Yield Stress Temperature Variations of the Yield Stress and Work-hardening Rate Yield Stress Peak Temperature (Single Crystals) Yield Stress Peak Temperature (Polycrystals) Conclusion About the Peak Temperature for the Yield Stress The Temperature of the Work-hardening Peak in Single Crystals The Temperature of the Work-hardening Peak in Polycrystals 394
9 xviii Contents Conclusions About the Peak in Work-Hardening The Role of Different Fault Energies Strength and Dislocation Density ~ Values of Dislocation Densities in Ni 3 Al Dislocation Densities and Mechanical parameters Stress Anomalies in other Intermetallics Other LI 2 Crystals B2 Alloys Deformation Mechanisms in p CuZn FeAl Compounds Conclusion on Strength Anomalies in Ordered intermetallics Creep behaviour of Ni 3 Al Compounds Conclusions J 411 References 411 CONCLUSION 417 GLOSSARY OF SYMBOLS 419 INDEX 425
Introduction to Materials Science
EPMA Powder Metallurgy Summer School 27 June 1 July 2016 Valencia, Spain Introduction to Materials Science Prof. Alberto Molinari University of Trento, Italy Some of the figures used in this presentation
More informationChapter 8 Strain Hardening and Annealing
Chapter 8 Strain Hardening and Annealing This is a further application of our knowledge of plastic deformation and is an introduction to heat treatment. Part of this lecture is covered by Chapter 4 of
More informationHarper Dorn Creep. Chapter 4
Chapter 4 Harper Dorn Creep Another mechanism for creep at high temperatures and low stresses was proposed in 1957 by Harper and Dorn [50] based on previous studies by Mott [295] and Weertman [189]. This
More informationEngineering Materials 2
-951-5- Engineering Materials 2 An Introduction to Microstructures, Processing and Design Third Edition Michael F. Ashby and David R. H. Jones Department of Engineering, Cambridge University, UK ELSEVIER
More informationSTRENGTHENING MECHANISM IN METALS
Background Knowledge Yield Strength STRENGTHENING MECHANISM IN METALS Metals yield when dislocations start to move (slip). Yield means permanently change shape. Slip Systems Slip plane: the plane on which
More informationAircraft Structures B H. for engineering students. T. H. G. Megson ELSEVIER SAN FRANCISCO SINGAPORE SYDNEY TOKYO
Aircraft Structures for engineering students Fifth Edition T. H. G. Megson Sag- ELSEVIER AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Butterworth-Heinemann
More information4-Crystal Defects & Strengthening
4-Crystal Defects & Strengthening A perfect crystal, with every atom of the same type in the correct position, does not exist. The crystalline defects are not always bad! Adding alloying elements to a
More informationImperfections, Defects and Diffusion
Imperfections, Defects and Diffusion Lattice Defects Week5 Material Sciences and Engineering MatE271 1 Goals for the Unit I. Recognize various imperfections in crystals (Chapter 4) - Point imperfections
More information(a) Would you expect the element P to be a donor or an acceptor defect in Si?
MSE 200A Survey of Materials Science Fall, 2008 Problem Set No. 2 Problem 1: At high temperature Fe has the fcc structure (called austenite or γ-iron). Would you expect to find C atoms in the octahedral
More informationChapter 8. Deformation and Strengthening Mechanisms
Chapter 8 Deformation and Strengthening Mechanisms Chapter 8 Deformation Deformation and Strengthening Issues to Address... Why are dislocations observed primarily in metals and alloys? How are strength
More informationMechanical Properties
Mechanical Properties Elastic deformation Plastic deformation Fracture II. Stable Plastic Deformation S s y For a typical ductile metal: I. Elastic deformation II. Stable plastic deformation III. Unstable
More informationThe Structure of Materials
The Structure of Materials Samuel M. Allen Edwin L. Thomas Massachusetts Institute of Technology Cambridge, Massachusetts / John Wiley & Sons, Inc. New York Chichester Weinheim Brisbane Singapore Toronto
More informationChapter 4. Introduction to Dislocations
Chapter 4 Introduction to Dislocations The discrepancy between the theoretical and observed yield stresses of crystals Dislocations The Burgers vector Vector notation for dislocations Dislocations in the
More informationMesoscopic modelling and simulation of plasticity in fcc and bcc crystals: Dislocation intersections and mobility
Journal of Computer-Aided Materials Design, 5: 31 54, 1998. KLUWER/ESCOM 1998 Kluwer Academic Publishers. Printed in the Netherlands. Mesoscopic modelling and simulation of plasticity in fcc and bcc crystals:
More informationChapter Outline Dislocations and Strengthening Mechanisms. Introduction
Chapter Outline Dislocations and Strengthening Mechanisms What is happening in material during plastic deformation? Dislocations and Plastic Deformation Motion of dislocations in response to stress Slip
More informationIMPERFECTIONSFOR BENEFIT. Sub-topics. Point defects Linear defects dislocations Plastic deformation through dislocations motion Surface
IMPERFECTIONSFOR BENEFIT Sub-topics 1 Point defects Linear defects dislocations Plastic deformation through dislocations motion Surface IDEAL STRENGTH Ideally, the strength of a material is the force necessary
More informationMT 348 Outline No MECHANICAL PROPERTIES
MT 348 Outline No. 1 2009 MECHANICAL PROPERTIES I. Introduction A. Stresses and Strains, Normal and Shear Loading B. Elastic Behavior II. Stresses and Metal Failure A. ʺPrincipal Stressʺ Concept B. Plastic
More informationThree stages: Annealing Textures. 1. Recovery 2. Recrystallisation most significant texture changes 3. Grain Growth
Three stages: Annealing Textures 1. Recovery 2. Recrystallisation most significant texture changes 3. Grain Growth Cold worked 85% Cold worked 85% + stress relieved at 300 C for 1 hr Cold worked 85% +
More information3. Cubic zirconia single crystals
3.1. Structure and phase relationship of cubic zirconium dioxide 3. Cubic zirconia single crystals 3.1. Structure and phase relationship of cubic zirconium dioxide Pure zirconia (ZrO 2 ) undergoes two
More informationRecent development of modelling techniques in nano- and meso-scale simulations of dislocation dynamics
Recent development of modelling techniques in nano- and meso-scale simulations of dislocation dynamics Department for Microstructure Physics and Alloy Design, Düsseldorf, Germany S.M. Hafez Haghighat,
More informationRecombination-Enhanced Dislocation Motion in SiGe and Ge
I. Yonenaga et al.: Recombination-Enhanced Dislocation Motion in SiGe and Ge 35 phys. stat. sol. (a) 171, 35 (1999) Subject classification: 61.72.Lk; 61.72.Ff; 62.20. ±x; S5.12; S6 Recombination-Enhanced
More informationMaterials Issues in Fatigue and Fracture. 5.1 Fundamental Concepts 5.2 Ensuring Infinite Life 5.3 Failure 5.4 Summary
Materials Issues in Fatigue and Fracture 5.1 Fundamental Concepts 5.2 Ensuring Infinite Life 5.3 Failure 5.4 Summary 1 A simple view of fatigue 1. Will a crack nucleate? 2. Will it grow? 3. How fast will
More informationCREEP CREEP. Mechanical Metallurgy George E Dieter McGraw-Hill Book Company, London (1988)
CREEP CREEP Mechanical Metallurgy George E Dieter McGraw-Hill Book Company, London (1988) Review If failure is considered as change in desired performance*- which could involve changes in properties and/or
More informationCHAPTER 6 OUTLINE. DIFFUSION and IMPERFECTIONS IN SOLIDS
CHAPTER 6 DIFFUSION and IMPERFECTIONS IN SOLIDS OUTLINE 1. TYPES OF DIFFUSIONS 1.1. Interdiffusion 1.2. Selfdiffusion 1.3.Diffusion mechanisms 1.4.Examples 2. TYPES OF IMPERFECTIONS 2.1.Point Defects 2.2.Line
More informationModule-6. Dislocations and Strengthening Mechanisms
Module-6 Dislocations and Strengthening Mechanisms Contents 1) Dislocations & Plastic deformation and Mechanisms of plastic deformation in metals 2) Strengthening mechanisms in metals 3) Recovery, Recrystallization
More informationDISLOCATIONS. Edge dislocation Screw dislocation Dislocations in crystals
Edge dislocation Screw dislocation Dislocations in crystals Further reading DISLOCATIONS Part of Introduction to Dislocations D. Hull and D.J. Bacon Pergamon Press, Oxford (1984) Advanced reading (comprehensive)
More informationImperfections: Good or Bad? Structural imperfections (defects) Compositional imperfections (impurities)
Imperfections: Good or Bad? Structural imperfections (defects) Compositional imperfections (impurities) 1 Structural Imperfections A perfect crystal has the lowest internal energy E Above absolute zero
More informationMovement of edge and screw dislocations
Movement of edge and screw dislocations Formation of a step on the surface of a crystal by motion of (a) n edge dislocation: the dislocation line moves in the direction of the applied shear stress τ. (b)
More informationDislocations & Materials Classes. Dislocation Motion. Dislocation Motion. Lectures 9 and 10
Lectures 9 and 10 Chapter 7: Dislocations & Strengthening Mechanisms Dislocations & Materials Classes Metals: Disl. motion easier. -non-directional bonding -close-packed directions for slip. electron cloud
More informationAtomistic Modeling of Thermally Activated Processes for Crystal Dislocations
IPAM Workshop ELWS 2 UCLA, Oct 16-20, 2017 Atomistic Modeling of Thermally Activated Processes for Crystal Dislocations Oct 16, 2017 Wei Cai, Xiaohan Zhang, William Kuykendall* Department of Mechanical
More informationAtomic structure, arrangement, and movement Introduction to Materials Introduction Types of Materials Structure-Property-Processing Relationship
Atomic structure, arrangement, and movement to Materials Types of Materials Structure-Property-Processing Relationship Environmental Effects on Material Behavior Materials Design and Selection Atomic Structure
More informationCHAPTER INTRODUCTION
1 CHAPTER-1 1.0 INTRODUCTION Contents 1.0 Introduction 1 1.1 Aluminium alloys 2 1.2 Aluminium alloy classification 2 1.2.1 Aluminium alloys (Wrought) 3 1.2.2 Heat treatable alloys (Wrought). 3 1.2.3 Aluminum
More informationA discrete dislocation plasticity analysis of grain-size strengthening
Materials Science and Engineering A 400 401 (2005) 186 190 A discrete dislocation plasticity analysis of grain-size strengthening D.S. Balint a,, V.S. Deshpande a, A. Needleman b, E. Van der Giessen c
More informationStrengthening Mechanisms
ME 254: Materials Engineering Chapter 7: Dislocations and Strengthening Mechanisms 1 st Semester 1435-1436 (Fall 2014) Dr. Hamad F. Alharbi, harbihf@ksu.edu.sa November 18, 2014 Outline DISLOCATIONS AND
More informationHigh temperature applications
3. CREEP OF METALS Lecturer: Norhayati Ahmad High temperature applications -Steel power plants -Oil refineries -Chemical plants High operating temperatures Engine jet ----1400 o C Steam turbine power plants:
More informationCHAPTER 4 NANOINDENTATION OF ZR BY MOLECULAR DYNAMICS SIMULATION. Introduction to Nanoindentation
CHAPTER 4 NANOINDENTATION OF ZR BY MOLECULAR DYNAMICS SIMULATION Introduction to Nanoindentation In Chapter 3, simulations under tension are carried out on polycrystalline Zr. In this chapter, nanoindentation
More informationThe Science and Engineering of Materials, 4 th ed Donald R. Askeland Pradeep P. Phulé. Chapter 7 Strain Hardening and Annealing
The Science and Engineering of Materials, 4 th ed Donald R. Askeland Pradeep P. Phulé Chapter 7 Strain Hardening and Annealing 1 Objectives of Chapter 7 To learn how the strength of metals and alloys is
More informationContents. PREFACE TO THE FOURTH EDITION... xiii ACKNOWLEDGEMENTS...xv GENERAL INTRODUCTION... xvii
Contents PREFACE TO THE FOURTH EDITION... xiii ACKNOWLEDGEMENTS...xv GENERAL INTRODUCTION... xvii Part A Metals CHAPTER 1 Metals...3 1.1 Introduction... 3 1.2 Metals for a Model Steam Engine... 3 1.3 Metals
More informationLecture # 11 References:
Lecture # 11 - Line defects (1-D) / Dislocations - Planer defects (2D) - Volume Defects - Burgers vector - Slip - Slip Systems in FCC crystals - Slip systems in HCP - Slip systems in BCC Dr.Haydar Al-Ethari
More informationGamma Titanium Aluminide Alloys
Fritz Appel, Jonathan David Heaton Paul, and Michael Oehring Gamma Titanium Aluminide Alloys Science and Technology WILEY- VCH WILEY-VCH Verlag GmbH & Co. KG aa I' Preface XIII Figures-Tables Acknowledgement
More informationDislocation Core Effects on Mobility
Dislocation Core Effects on Mobility Wei Cai 1, Vasily V. Bulatov 1, Jinpeng Chang 2, Ju Li 2 and Sidney Yip 2 1 Lawrence Livermore National Laboratory, University of California, Livermore, CA 94551 2
More informationSome aspects of cross-slip mechanisms in metals and alloys
Some aspects of crossslip mechanisms in metals and alloys Daniel Caillard, J.L. Martin To cite this version: Daniel Caillard, J.L. Martin. Some aspects of crossslip mechanisms in metals and alloys. Journal
More informationImperfections in the Atomic and Ionic Arrangements
Objectives Introduce the three basic types of imperfections: point defects, line defects (or dislocations), and surface defects. Explore the nature and effects of different types of defects. Outline Point
More informationThe high temperature decrease of the critical resolved shear stress in nickel-base superalloys
Materials Science and Engineering A319 321 (2001) 383 387 www.elsevier.com/locate/msea The high temperature decrease of the critical resolved shear stress in nickel-base superalloys M. Kolbe * Institute
More informationStrengthening Mechanisms. Today s Topics
MME 131: Lecture 17 Strengthening Mechanisms Prof. A.K.M.B. Rashid Department of MME BUET, Dhaka Today s Topics Strengthening strategies: Grain strengthening Solid solution strengthening Work hardening
More informationMaterials Science and Engineering: An Introduction
Materials Science and Engineering: An Introduction Callister, William D. ISBN-13: 9780470419977 Table of Contents List of Symbols. 1 Introduction. 1.1 Historical Perspective. 1.2 Materials Science and
More informationCreep and High Temperature Failure. Creep and High Temperature Failure. Creep Curve. Outline
Creep and High Temperature Failure Outline Creep and high temperature failure Creep testing Factors affecting creep Stress rupture life time behaviour Creep mechanisms Example Materials for high creep
More informationHydrogen effects on the plasticity of face centred cubic (fcc) crystals
Hydrogen effects on the plasticity of face centred cubic (fcc) crystals David Delafosse To cite this version: David Delafosse. Hydrogen effects on the plasticity of face centred cubic (fcc) crystals. Richard
More informationLectures on: Introduction to and fundamentals of discrete dislocations and dislocation dynamics. Theoretical concepts and computational methods
Lectures on: Introduction to and fundamentals of discrete dislocations and dislocation dynamics. Theoretical concepts and computational methods Hussein M. Zbib School of Mechanical and Materials Engineering
More informationChapter 7: Dislocations and strengthening mechanisms. Strengthening by grain size reduction
Chapter 7: Dislocations and strengthening mechanisms Mechanisms of strengthening in metals Strengthening by grain size reduction Solid-solution strengthening Strain hardening Recovery, recrystallization,
More informationWhy are dislocations observed primarily in metals CHAPTER 8: DEFORMATION AND STRENGTHENING MECHANISMS
Why are dislocations observed primarily in metals CHAPTER 8: and alloys? DEFORMATION AND STRENGTHENING MECHANISMS How are strength and dislocation motion related? How do we manipulate properties? Strengthening
More informationInteractions Oxidation Mechanical behavior
Interactions Oxidation Mechanical behavior Eric Andrieu CIRIMAT-INP Toulouse-UMR 5085 ANF en Métallurgie. Aussois 22 au 25 Octobre 2012 Outline Scientific and experimental background Basic mechanisms affecting
More informationExtended defects in semiconductors studied by positron annihilation
Colloquium DES Poitiers 2003 Extended defects in semiconductors studied by positron annihilation Hartmut S. Leipner Interdisziplinäres Zentrum für Materialwissenschaften Martin-Luther-Universität Halle
More informationRECRYSTALLIZATION OF ORDERED MATERIALS
Chapter 8 RECRYSTALLIZATION OF ORDERED MATERIALS 8.1 INTRODUCTION There is significant interest in the use of ordered intermetallic compounds as high temperature structural materials. However, use of these
More informationMobility laws in dislocation dynamics simulations
Materials Science and Engineering A 387 389 (2004) 277 281 Mobility laws in dislocation dynamics simulations Wei Cai, Vasily V. Bulatov Lawrence Livermore National Laboratory, University of California,
More informationHydrogen in Semiconductors
Hydrogen in Semiconductors SEMICONDUCTORS AND SEMIMETALS Volume 34 Volume Editors JACQUES I. PANKOVE UNIVERSITY OF COLORADO AT BOULDER BOULDER, COLORADO NOBLE M. JOHNSON XEROX PALO ALTO RESEARCH CENTER
More informationElectron channelling contrast imaging (ECCI) an amazing tool for observations of crystal lattice defects in bulk samples
Electron channelling contrast imaging (ECCI) an amazing tool for observations of crystal lattice defects in bulk samples Stefan Zaefferer with contributions of N. Elhami, (general & steels) Z. Li F. Ram,
More information1. Recent progress in shuffle-glide controversy in silicon. At high temperature, it is widely accepted that glide-set dislocation (Figure.
1. Recent progress in shuffle-glide controversy in silicon Memorandum by Satoshi Izumi 12/11/2007 1.1. Dislocation Mobility At high temperature, it is widely accepted that glide-set dislocation (Figure.1)
More informationTutorial 2 : Crystalline Solid, Solidification, Crystal Defect and Diffusion
Tutorial 1 : Introduction and Atomic Bonding 1. Explain the difference between ionic and metallic bonding between atoms in engineering materials. 2. Show that the atomic packing factor for Face Centred
More informationDept.of BME Materials Science Dr.Jenan S.Kashan 1st semester 2nd level. Imperfections in Solids
Why are defects important? Imperfections in Solids Defects have a profound impact on the various properties of materials: Production of advanced semiconductor devices require not only a rather perfect
More informationATOMISTIC STUDIES OF DISLOCATION GLIDE IN γγγ-tial
Mat. Res. Soc. Symp. Proc. Vol. 753 2003 Materials Research Society BB4.3. ATOMISTIC STUDIES OF DISLOCATION GLIDE IN γγγ-tial R. Porizek*, S. Znam*, D. Nguyen-Manh**, V. Vitek* and D. G. Pettifor** *Department
More informationTwins & Dislocations in HCP Textbook & Paper Reviews. Cindy Smith
Twins & Dislocations in HCP Textbook & Paper Reviews Cindy Smith Motivation Review: Outline Crystal lattices (fcc, bcc, hcp) Fcc vs. hcp stacking sequences Cubic {hkl} naming Hcp {hkil} naming Twinning
More informationLecture 12: High Temperature Alloys
Part IB Materials Science & Metallurgy H. K. D. H. Bhadeshia Course A, Metals and Alloys Lecture 12: High Temperature Alloys Metallic materials capable of operating at ever increasing temperatures are
More informationMetal working: Deformation processing II. Metal working: Deformation processing II
Module 28 Metal working: Deformation processing II Lecture 28 Metal working: Deformation processing II 1 Keywords : Difference between cold & hot working, effect of macroscopic variables on deformation
More informationDislocations Linear Defects
Dislocations Linear Defects Dislocations are abrupt changes in the regular ordering of atoms, along a line (dislocation line) in the solid. They occur in high density and are very important in mechanical
More informationME 254 MATERIALS ENGINEERING 1 st Semester 1431/ rd Mid-Term Exam (1 hr)
1 st Semester 1431/1432 3 rd Mid-Term Exam (1 hr) Question 1 a) Answer the following: 1. Do all metals have the same slip system? Why or why not? 2. For each of edge, screw and mixed dislocations, cite
More informationChapter 7 Dislocations and Strengthening Mechanisms. Dr. Feras Fraige
Chapter 7 Dislocations and Strengthening Mechanisms Dr. Feras Fraige Chapter Outline Dislocations and Strengthening Mechanisms What is happening in material during plastic deformation? Dislocations and
More informationCommon Operating Problems
SYDNEY Pressure Vessels Field Manual Common Operating Problems and Practical Solutions Maurice Stewart Oran T. Lewis AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE
More informationdoi: /
doi: 10.1063/1.362881 Influence of oxygen precipitation along dislocations on the strength of silicon crystals Ichiro Yonenaga and Koji Sumino a) Institute for Materials Research, Tohoku University, Sendai
More informationASTM Conference, May , Hilton Head Island, SC
ASTM Conference, May 17 2016, Hilton Head Island, SC Understanding Irradiation Growth through Atomistic Simulations: Defect Diffusion and Clustering in Alpha-Zirconium and the Influence of Alloying Elements
More information26. Irradiation Induced Mechanical Property Changes: Hardening and Embrittlement
26. Irradiation Induced Mechanical Property Changes: Hardening and Embrittlement 26.1 Introduction... 2 26.2. Changes in the Stress-strain curve after irradiation... 2 26.3 Hardening by Irradiation induced
More informationThe Dislocation Basis of Yield and Creep
The Dislocation Basis of Yield and Creep David Roylance Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, MA 02139 March 22, 2001 Introduction Phenomenological
More informationShort-Circuit Diffusion L6 11/14/06
Short-Circuit Diffusion in Crystals 1 Today s topics: Diffusion spectrum in defective crystals Dislocation core structure and dislocation short circuits Grain boundary structure Grain boundary diffusion
More informationMaterials and their structures
Materials and their structures 2.1 Introduction: The ability of materials to undergo forming by different techniques is dependent on their structure and properties. Behavior of materials depends on their
More informationBAUSCHINGER EFFECT IN Nb AND V MICROALLOYED LINE PIPE STEELS. Andrii Gennadiovych Kostryzhev
BAUSCHINGER EFFECT IN Nb AND V MICROALLOYED LINE PIPE STEELS by Andrii Gennadiovych Kostryzhev A thesis submitted to The University of Birmingham for the degree of DOCTOR OF PHILOSOPHY School of Metallurgy
More informationPlastic Deformation in Crystalline Materials. Lecture 1: Overview. Kamyar Davoudi Fall 2015
Plastic Deformation in Crystalline Materials Lecture 1: Overview Kamyar Davoudi Fall 2015 1 Structure of Solids Single Crystalline Crystalline Poly Crystalline Solids: amorphous Quasi-crystalline * (ordered
More informationAnalyzing Method of Hydrogen Trapping Sites in Metal Crystals and the Relationship between Surface Defects and Hydrogen Absorption.
Analyzing Method of Hydrogen Trapping Sites in Metal Crystals and the Relationship between Surface Defects and Hydrogen Absorption Gen Katano KEK, High Energy Accelerator Research Organization, Japan Introduction
More informationLiquid Metal Embrittlement An introduction
Liquid Metal Embrittlement An introduction Véronique Ghetta, Dominique Gorse & Vassilis Pontikis Outline Environment & Mechanical behavior What is LME? Fundamentals of mechanical failure Experimental facts
More informationABSTRACT. amorphous metals, and utilized the correlation between elastic properties and fragility as a
ABSTRACT In the present thesis study, we combined molecular dynamics (MD) simulations and experiments to systematically investigate the Debye-Grüneisen thermal expansion effect and configurational potential
More informationIntroduction to Engineering Materials ENGR2000 Chapter 7: Dislocations and Strengthening Mechanisms. Dr. Coates
Introduction to Engineering Materials ENGR2000 Chapter 7: Dislocations and Strengthening Mechanisms Dr. Coates An edge dislocation moves in response to an applied shear stress dislocation motion 7.1 Introduction
More informationfactured pillars, even though the strength is significantly higher than in the bulk. These yield stress values, y
Abstract The size effect in body-centered cubic (bcc) metals was comprehensively investigated through microcompression tests performed on focused ion beam machined tungsten (W), molybdenum (Mo) and niobium
More informationCONTENTS PART II. MAGNETIC PROPERTIES OF MATERIALS
PART I. INTRODUCTION 1. CONCEPTS OF FERROMAGNETISM I Magnetic Field 1 Intensity of Magnetization and Magnetic Induction 2 Magnetization and Permeability Curves 3 Hysteresis Loop 4 Ferromagnetism, Paramagnetism
More informationProblems to the lecture Physical Metallurgy ( Materialkunde ) Chapter 6: Mechanical Properties
Institut für Metallkunde und Metallphysik Direktor: Prof. Dr. rer. nat. Günter Gottstein RWTH Aachen, D-52056 Aachen Internet: http://www.imm.rwth-aachen.de E-mail: imm@imm.rwth-aachen.de Tel.: +49 241
More informationDefects and Diffusion
Defects and Diffusion Goals for the Unit Recognize various imperfections in crystals Point imperfections Impurities Line, surface and bulk imperfections Define various diffusion mechanisms Identify factors
More informationExploring Engineering
Exploring Engineering An Introduction to Engineering and Design Third Edition Philip Kosky Robert Balmer William Keat George Wise ELSEVIER AMSTERDAM BOSTON HI'IDIU.HURG LONDON * NliW YORK OXFORD PARIS
More informationChapter 1. The Structure of Metals. Body Centered Cubic (BCC) Structures
Chapter 1 The Structure of Metals Body Centered Cubic (BCC) Structures Figure 1. The body-centered cubic (bcc) crystal structure: (a) hard-ball model; (b) unit cell; and (c) single crystal with many unit
More informationDepartment of Materials Science and Engineering Massachusetts Institute of Technology 3.14 Physical Metallurgy Fall 2003 Exam I
Department of Materials Science and Engineering Massachusetts Institute of Technology 3.14 Physical Metallurgy Fall 2003 Exam I 3 2.5 2 Frequency 1.5 1 0.5 0 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
More informationFirst stages of plasticity in nano- and micro-objects: simulations and experiments
First stages of plasticity in nano- and micro-objects: simulations and experiments Sandrine BROCHARD, Jean-Luc DEMENET, Julien GODET, Julien GUENOLE (PhD student), Dominique EYIDI, Laurent PIZZAGALLI,
More informationChapter 8: Strain Hardening and Annealing
Slide 1 Chapter 8: Strain Hardening and Annealing 8-1 Slide 2 Learning Objectives 1. Relationship of cold working to the stress-strain curve 2. Strain-hardening mechanisms 3. Properties versus percent
More informationModule #8. Defects in Crystalline Materials. READING LIST DIETER: Ch. 4, Pages
HOMEWORK From Dieter 4-6 Module #8 Defects in Crystalline Materials READING LIST DIETER: Ch. 4, Pages 103-114 Ch. 4, Pages 103-117 in Meyers & Chawla, 1 st ed. Ch. 1, Pages 1-26 in Argon Property Structure,
More informationWrought Aluminum I - Metallurgy
Wrought Aluminum I - Metallurgy Northbrook, IL www.imetllc.com Copyright 2015 Industrial Metallurgists, LLC Course learning objectives Explain the composition and strength differences between the alloy
More informationFatigue and Fracture of Austenitic Stainless Steels
UNIVERSITY OF TORONTO Fatigue and Fracture of Austenitic Stainless Steels 12/2/2013 An investigation into the fatigue phenomenon of austenitic (face-centered cubic) stainless steels Table of Contents List
More informationThe University of Jordan School of Engineering Chemical Engineering Department
The University of Jordan School of Engineering Chemical Engineering Department 0905351 Engineering Materials Science Second Semester 2016/2017 Course Catalog 3 Credit hours.all engineering structures and
More informationDislocation processes during the plastic deformation of c -TiAl
PHILOSOPHICAL MAGAZINE A, 1999, VOL. 79, NO. 5, 1045± 1071 Dislocation processes during the plastic deformation of c -TiAl D. Haïussler², M. Bartsch², M. Aindow, I. P. Jones and U. Messerschmidt² ² Max
More informationPlastic deformation of yttria stabilized cubic zirconia single crystals I. Activation parameters of deformation
phys. stat. sol. (a) 201, No. 1, 26 45 (2004) / DOI 10.1002/pssa.200306715 Plastic deformation of yttria stabilized cubic zirconia single crystals I. Activation parameters of deformation A. Tikhonovsky,
More informationRecrystallization. Chapter 7
Chapter 7 Recrystallization 7.1 INTRODUCTION The earlier chapters have described creep as a process where dislocation hardening is accompanied by dynamic recovery. It should be discussed at this point
More informationThermodynamics of. Turbomachinery. Fluid Mechanics and. Sixth Edition. S. L. Dixon, B. Eng., Ph.D. University of Liverpool, C. A. Hall, Ph.D.
Fluid Mechanics and Thermodynamics of Turbomachinery Sixth Edition S. L. Dixon, B. Eng., Ph.D. Honorary Senior Fellow, Department of Engineering, University of Liverpool, UK C. A. Hall, Ph.D. University
More information3, MSE 791 Mechanical Properties of Nanostructured Materials
3, MSE 791 Mechanical Properties of Nanostructured Materials Module 3: Fundamental Physics and Materials Design Lecture 1 1. What is strain (work) hardening? What is the mechanism for strain hardening?
More informationANISOTROPY OF ACOUSTIC EMISSION AND PORTEVIN LE CHÂTELIER PHENOMENA IN POLYCRYSTALLINE ALUMINIUM ALLOYS SUBJECTED TO TENSILE TESTS Z.
ARCHIVES OF ACOUSTICS 31, 4 (Supplement), 75 81 (2006) ANISOTROPY OF ACOUSTIC EMISSION AND PORTEVIN LE CHÂTELIER PHENOMENA IN POLYCRYSTALLINE ALUMINIUM ALLOYS SUBJECTED TO TENSILE TESTS A. PAWEŁEK, J.
More information