Ultrafine Grained Materials II E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 1264

Veröffentlichungsjahr: 2013

Beschreibung

Proceedings of a symposium sponsored by the Shaping and Forming Committee of the Materials Processing and Manufacturing Division (MPMD) and the Mechanical Behavior Committee (Jt. SMD/ASM-MSCTS) of the Structural Materials Division (SMD) of TMS (The Minerals, Metals & Materials Society) and held during the 2002 TMS Annual Meeting in Seattle, Washington February 17-21,2002.

Leseprobe

Contents

Cover

Half Title page

Title page

Copyright page

Preface

I. Microstructural Evolution

High Strain Monotonic Deformation-Structure and Strength

Abstract

Introduction

Microstructural Evolution

Microstructure and Flow Stress

Concluding Remarks

Acknowledgements

References

Influence of Processing Route on Microstructure and Grain Boundary Development During Equal-Channel Angular Pressing of Pure Aluminum

Abstract

Introduction

Experimental Background

Results and Discussion

Conclusions

Acknowledgement

References

Equal Channel Angular Pressing of Steels (BCC), Al Alloys (FCC) and Pure Titanium (HCP)

Abstract

Introduction

Experimental Procedure

Results and Discussion

Summary

Acknowledgement

References

The Effect of Strain Per Pass on the Microstructure Developed in Aluminum Processed by Equal Channel Angular Extrusion

Abstract

Introduction

Experimental

Results and Discussion

Conclusion

Acknowledgements

Reference

Microstructural Evolution of Titanium Under Twist Extrusion

Abstract

Introduction

The Main Idea behind the TE Method

Experimental Investigation

Conclusion

References

Nanostructure Formation and Carbides Dissolution in Rail Steel Deformed by High Pressure Torsion

Abstract

1. Introduction.

2. Experimental procedure.

3. Results.

4. Discussion.

4. Conclusions

Acknowledgements

References:

Grain Refinement and Texture Development in Asymmetrically Rolled Aluminum Alloy Sheets

Abstract

1. Introduction

2. Experimetnal

3. Results and Discussion

4. Conclusion

Acknowledgement

Reference

Ultrafine Grain Formation During Equal Channel Angular Extrusion in an Al-Mg-Sc Alloy

Abstract

1. Introduction

2. Experimental Material and Procedure

3. Results

4. Discussion

5. Conclusions

Acknowledgment

References

Formation of Nanocrystalline Structure in a Ni-20 % Cr Alloy

Abstract

1. Introduction

2. Materials and Experimental Technique

3. Results

4. Discussion

References

Formation of Ultrafine Grains During Intense Plastic Straining in An Al-Li Alloy at 400°C

Abstract

Introduction

Experimental

Experimental Results

Discussion

Summary and Conclusions.

Referens

Mechanisms of Formation of Submicron Grain Structures During Severe Deformation

Abstract

1. Introduction

2. Grain Refinement during Severe Deformation

3. Conclusions

Acknowledgements

References

Grain Refining Mechanism of Ti During Equal Channel Angular Pressing

Abstract

1. Introduction

2. Experimental Procedures

3. Results and discussion

4. Summary

References

Microstructure Evolution in Nanocrystal Formation During Ball Milling

Abstract

Introduction

Experimental Procedures

Results

Discussion

Conclusions

References

Formation of Nanocrystalline Structure in Two-Phase Titanium Alloys by Warm Severe Plastic Deformation

Abstract

Introduction

Results

Summary

Acknowledgdement

References

Evolution of Microstructure and Mechanical Behavior of Titanium During Warm Multiple Deformation

Abstract

Introduction

Experimental Procedure

Results

Discussion

Summary

Acknowledgement

References

Effect of Pressure on the Final Grain Size After High Pressure Torsion

Abstract

Introduction

Experimental Material and Procedure

Experimental Results

Summary

Acknowledgement

References

Heterogeneous Microstructural Evolution and Reactions During Repeated Intense Deformation

Abstract

Introduction

Microstructural Changes of Multilayers during Cold-Rolling

Nanocrystallization by Mechanical Deformation of Amorphous Precursors

Summary

Acknowledgement

References

Hardness and Microstructure Changes in Severely Deformed and Recrystallized Tantalum

Abstract

Introduction

Experimental Procedures

Results and Discussion

Conclusions

Acknowledgements

References

II. Processing of Ultrafine-Grained Materials

Homogeneity in Ultrafine-Grained Aluminum Prepared by Equal-Channel Angular Pressing

Abstract

Introduction

Experimental Material and Procedures

Experimental Results

Discussion

Summary and Conclusions

Acknowledgement

References

Processing of an Aluminum-6061 Metal Matrix Composite by Equal-Channel Angular Pressing

Abstract

Introduction

Experimental material and procedures

Experimental results and discussion

Summary and Conclusions

Acknowledgement

References

Grain Refinement and Phase Transformations in Al and Fe Based Alloys During Severe Plastic Deformation

Abstract

1. Introduction

2. Experimental Procedure

3. Results and Discussions

4. Conclusions

Acknowledgement

References

Phase Transformations in Ultrafine Grained Fe and Fe-Mn Alloys

Abstract

Introduction

Experimental

Results and Discussion

Conclusions

References

Ultrafine-Grained Tungsten Produced by SPD Techniques

Abstract

Introduction

Materials and Experimetnal Procedures

Experimetnal Results

Discussion

Conclusions

Achnowledegement

References

Metastable Nanostructured Alloys Processed by Severe Plastic Deformation

Abstract

Introduction

Experimental Procedures

Results

Discussion

Summary

Acknowledgement

References

Syntheses of Nd2Ti2O7/Al2O3 Nanocomposites by Spark-Plasma-Sintering and High-Energy Ball-Milling

Abstract

1. Introduction

2. Experimental procedures

3. Results and Discussion

4. Conclusions

Acknowledgements:

References

Properties and Microstructure of Alumina-Niobium Nanocomposites Made by Novel Processing Methods

Abstract

Introduction

Experimental Procedures

Results and Discussion

Conclusions

Acknowledgements:

References

Nano-Nano Composites of Silicon Nitride and Silicon Carbide

Abstract

1. Introduction

2. Experimental Procedure

3. Results and Discussion

4. Conclusion

Acknowledgement

References

The Use of SPD for Fabrication of Bulk Nanostructured Materials from Ball-Milled Powders

Abstract

1. Introduction

2. Experimental.

3. Results and discussion.

Conclusion

References

Numerical Analysis of Plastic Deformation in Constrained Groove Pressing

Abstract

1. Introduction

2. Constrained Groove Pressing (CGP)

3. Numerical Analysis of CGP

4. Constrained Grooved Rolling (CGR)

5. Conclusion

Acknowledgement

References

Effect of Vanadium Addition on Dynamic γ→α Transformation During Hot Deformation of Low Carbon Steels

Abstract

Introduction

Experimental Procedure

Measurement of Volume Fraction of Dynamically Transformed Ferrite [6]

Results

Discussion

Conclusions

Reference

Determination of Dynamic Ferrite Transformation During Deformation in Austenite

Abstract

1. Introduction

2. Experimental Procedure

3. Results and Discussion

Conclusions

Reference

Grain Refinement of Medium Carbon Steel Withcontrolled Thermo-Mechanical Deformation

Abstract

Introduction

Experimental

Results and Discussion

Conclusions

Acknowledgments

References

Enhanced Formability of Superplastic AlMgZr Alloys Made by Particulate Routes

Abstract

Introduction

Particulate Manufacture

Particulate Processing

Microstructural Analysis

Solidification Modelling

High Speed Atomisation

Conclusions

Symbols

Acknowledgements

References

On The Development of Microstructure in A Metal Matrix Composite Using Nano–Materials

Abstract

Introduction

Processing and Characterization Procedures

Microstructure and Microstructural Evolution

Conclusions

References

A New Severe Plastic Deformation Methd: Twist Extrusion

Abstract

Introduction

References

III. Structure and Mechanical Properties

Defects, Microstructure and Dislocation Activity in Nanocrystalline Metals

Abstract

Introduction

Microstructural Factors Affecting Mechanical Behavior

Mechanisms of Deformation

Fracture Toughness and Strain to Failure

Conclusions

Acknowledgments

References

Recent Developments of SPD Processing for Fabrication of Bulk Nanostructured Materials

Abstract

1. Introduction

2. Investigations and development of SPD processing

3. Microstructural Features and Enhancement of Properties

Summary and Conclusions.

Acknowledgements

References

Deformation Mechanisms at Different Grain Sizes in a Cryogenically Ball-Milled Al-Mg Alloy

Abstract

Introduction

Experimental procedures

Results and Discussion

Conclusion

Acknowledgments

References

Properties and Nanostructures of Materials Processed by SPD Techniques

Abstract

1. Introduction

2. Mechanical Properties

3. Nanostructures

4. Conclusions

Acknowledgement

References

Tensile and Fatigue Properties of Al-Mg-Sc-Zr Alloy Fine-Grained by Equal-Channel Angular Pressing

Abstract

1. Introduction

2. Experimental Procedure

3. Experimental Results

Summary

Acknowledgements

References

Structure, Properties and Thermal Stability of Utra-Fine Grained Cu-Cr-Zr Alloy

Abstract

1. Introduction

2. Experimental

3. Results

5. Summary

Acknowledgements

References

Corrosion Fatigue of Ultra-Fine Grain Copper Fabricated by Severe Plastic Deformation

Abstract

1. Introduction

2. Experimental Procedure

3. Results and Discussions.

Summary

References

Strength of Submicrocrystalline Severely Deformed Commercial Aluminum Alloys

Abstract

Introduction

Tensile Strength of Submicrocrystalline Aluminum Alloys

Conclusions

References

Machinability Studies of PM Metal Matrix Composites on EDM

Abstract

1. Introduction

2. Experimental Plan

3. Results and Discussion

4. Conclusions

References

Mechanical Properties of Ultrafine Grained Aluminum and Ultra low Carbon Steel Produced by ARB Process

Abstract

Introduction

Experimental Procedures

Results and Discussions

Conclusions

Acknowledgments

References

Mechanical Properties of Nanostructured Plain Low-Carbon Steels Produced by Conventional Cold-Rolling and Annealing of Martensite Starting Microstructure

Abstract

Introduction

Experimental Procedures

Results

Discussions

Conclusions

Acknowledgments

References

Dry Sliding Wear Behavior of Ultrafine Grained Commercial Purity Aluminum and Low Carbon Steel Produced by Severe Plastic Deformation Techniques

Abstract

Introduction

Experimental

Results and Discussions

Conclusions

Acknowledgments

References

Structural Evolution of Ultrafine-Grained Copper and Copper-Based Alloy During Plastic Deformation

Abstract

1. Introduction

2. Materials and experimental technique

3. Results and their discussion

Acknowledgements

References

Microstructure and Properties of 7475 Aluminum Alloy After Equal-Channel Angular Pressing

Abstract

Introduction

Experimental, Material and Procedures

Results

Mechanical properties after ECAP

Discussion

5. SUMMARY AND CONCLUSIONS

Acknowledgement

References

The Microstructures and Compressive Deformation Behaviors of Nanocrystalline Al-5 at.% Ti Compacts Prepared by UHP-HP

Abstracts

1. Introduction

2. Experimental procedure

3. Results and discussion

4. Concluding Remarks

Acknowledgements

References

IV. Superplasticity and Thermal Stability

Grain Refinement of Copper Based Alloys Using ECAP

Abstract

Introduction

Experimental Materials and Procedures

Experimental Results and Discussion

Summary and Conclusions

Acknowledgements

References

Developing Superplasticity at High Strain Rates Through ECAP Processing

Abstract

Introduction

Grain refinement in ECAP

Superplasticity in the Al-Mg-Li-Zr Alloy

Superplasticity in the Al-Mg-Sc alloy

Summary and conclusions

Acknowledgements

References

Grain Refinement and Superplasticity in Magnesium Alloys

Abstract

Introduction

Superplasticity in Magnesium-Based Materials Processed by Powder Metallurgy Route Using Rapidly Solidified Powder

Superplasticity in Magnesium-Based Materials Processed by Severe Plastic Deformation

Conclusions

References

Effect of The Pressing Strain on the Annealing Behavior of Ultrafine Grained Ferrite in a Low Carbon Steel Fabricated by Equal Channel Angular Pressing

Abstract

Introduction

Experimental

Results and Discussion

Summary

Acknowledgment

References

Significance of Microstructural Thermal Stability in An Al-2219 Alloy Processed by Severe Plastic Deformation

Abstract

Introduction

Experimental Material and Procedures

Experimental Results

Discussion

Summary and Conclusions

Acknowledgements

References

Modelling The Microstructural Evolution During Annealing of A Severely Deformed Al-3% Mg Alloy

Abstract

Introduction

Experimental

Experimental Results

Isochronal annealing

Isothermal Annealing

Modelling

Conclusions

Acknowledgement

Reference

Structure and Stability of Ultrafine-Grained Materials. Role of Impurities and Second-Phase Particles.

Abstract

1. Introduction

2. Material and Method of Study

3. Results and Discussion

Acknowledgments

Reference

Annealing Effect on the Strength of Severe-Plastic-Deformed Titanium

Abstract

Introduction

Experimental

Results

Discussion

Conclusions

Acknowledgments.

References

Structure and Mechanical Behavior of the AMg6 Aluminum Alloy After Severe Plastic Deformation and Annealing

Abstract

Introduction

Experimental

Results and Discussion

Conclusions

References

V. Theory and Modeling

Continuum Mechanics Approach in Severe Plastic Deformation

Abstract

Introduction

Structure Evolution

Deformation Mode and History

Simple Shear versus Pure Shear

References

Deformation of Ti-6Al-4V Via Equal Channel Angular Extrusion

Abstract

Introduction

Materials and Procedures

Results and Discussion

Conclusions

Acknowledgements

References

Kinematics of Damage Governed by Severe Plastic Deformation

Abstract

Introduction

Correlation of Plastic Damage to the Density Change

The Kinetic Equation and Physical Model of Damage Accumulation and Recovery

Density Measurement Technique

Investigation of Density Change during Equal Channel Angular Extrusion (ECAE)

Investigation of Density Change during Equal Channel Angular Drawing (ECAD)

Discussion of Results

Conclusion

References

Strength and Ductility of Ultrafine Grained Metallic Materials

Abstract

Introduction

The Constitutive Mode

Tensile Ductility

Conclusion

Acknowledgements

References

Work Hardening Behavior of Aluminum Over a Wide Range of Strain

Abstract

Introduction

Experimental Material and Procedures

Experimental Results

Discussion

Summary and Conclusions

Acknowledgement

References

Analysis of Principal and Equivalent Strains in Equal Channel Angular Deformation

Abstract

Introduction

Analysis of Large Plastic Strains by Matrix Algebra

Analysis of Principal Strains in ECAD

Analysis of the “Equivalent” Strain in ECAD

5. Discussion

Summary

Acknowledgments

References

Polycrystal Constitutive Modeling of ECAP: Texture and Microstructural Evolution

Abstract

Introduction

Model Description

Results: Texture and Material Response

Results: Grain Refinement

Discussion and Future Work

Acknowledgement

Referenece

Grain Size, Size-Distribution and Dislocation Structure From Diffraction Peak Profile Analysis

Abstract

1. Introduction

2. Evaluation of Broadened Diffraction Peak Profiles

3. Experimental

4. Results and discussions

5. Conclusions

Acknowledgements

References

Defect Characterization of Equal Channel Angular Pressed Cu by Selective Annealing Treatment

Abstract

1. Introduction

2. Experimental

3. Results

4. Discussion

5. Summary and Conclusions

Acknowledgements

References

Size and Shape of Nano-Grains in Polycrystals Subjected to SPD

Abstract

Introduction

The Mean Grains Size

Grain Size Uniformity

Grain Size Effect

Characterization of the Grain Boundaries

Grain Shape

An Example of Applications

Final Remarks

References

X-Ray Analysis of SPD Nanostructured Materials

Abstract

Introduction

Experimental and Modeling Procedures

Results and Discussion

The peculiarities of SPD microstructure in SPD Ti and W

Summary

Acknowledgement

References

Addendum

Effects of Hot Working on Austenite/Ferrite Transformation in HSLA Steel

Abstract

1. Introduction

2. Experimental Procedures

3. Results and Discussion

4. Conclusions

Acknowledgements

References

Equal Channel Angular Processing of Magnesium Alloys

Abstract

Introduction

Experimental Procedures

Results and Discussion

Conclusions

Acknowledgements

References

Microstructural Evolution of Cryomilled Nanocrystalline Al-Ti-Cu Alloy

Abstract

Introduction

Experimental Procedures

Results and Discussion

Conclusion

Acknowledgements

Reference

Microstructure and Mechanical Properties of Non-Heat Treatable Aluminum Alloys Produced by Accumulative Roll Bonding Process

Abstract

Introduction

Experimental

Results and Discussion

Conclusions

Reference

Features of Severe Plastic Deformation as Compared to Conventional Deformation Modes

Abstract

1. Introduction

2. Characteristics of Severe Plastic Deformation

3. Comparison between Dynamic and Static Stress-Strain Characteristics under Varying Hydrostatic Pressure

4. Measurements of Defect Densities and Long Range Internal Stresses under Different Hydrostatic Pressure

5. Measurements and Mechanical Relevancy of Coherently Scattering Lattice Size

6. Conclusions

Acknowledgments

References

Author Index

Subject Index

Ultrafine Grained Materials II

A Publication of The Minerals, Metals & Materials Society184 Thorn Hill Road Warrendale, Pennsylvania 15086-7528(724) 776-9000

Visit the TMS web site athttp://www.tms.org

The Minerals, Metals & Materials Society is not responsible for statements or opinions and is absolved of liability due to misuse of information contained in this publication.

Library of Congress Catalog Number 2001097450ISBN Number 0-87339-523-9

Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by The Minerals, Metals & Materials Society for users registered with the Copyright Clearance Center (CCC) Transactional Reporting Service, provided that the base fee of $7.00 per copy is paid directly to Copyright Clearance Center, 27 Congress Street, Salem, Massachusetts 01970. For those organizations that have been granted a photocopy license by Copyright Clearance Center, a separate system of payment has been arranged.

© 2002

If you are interested in purchasing a copy of this book, or if you would like to receive the latest TMS publications catalog, please telephone[phone] (U.S. only) or 724-776-9000, EXT. 270.

PREFACE

Two complementary approaches have been developed to synthesize ultrafine-grained (UFG) materials with grain sizes in the range from 10 to 1000 nm. The first is the “bottom-up” approach in which bulk ultrafine-grained materials are assembled from individual atoms or nanoscale building blocks such as nano-particles. Gleiter’s pioneering work on inert gas condensation (IGC) is a typical example of this approach. Various chemical and physical methods have been developed to synthesize nano-powders for small-scale laboratory investigations as well as for large-scale commercial use. Ceramic and metallic nano-powders can now be readily purchased from an increasing number of nano-technology companies. However, consolidation of these nano-particles into bulk nanostructured materials remains a major challenge.

The second approach for producing UFG materials is the “top-down” approach in which coarse-grained materials are refined into UFG materials. The most successful “top-down” approach has been via severe plastic deformation (SPD) techniques among which the most developed are equal channel angular pressing (ECAP) and high-pressure torsion (HPT). Recently, new SPD techniques have been developed such as accumulative roll-bonding (ARB), multipass-coin-forging (MCF), multi-axis deformation, and repetitive corrugation and straightening (RCS). The main advantage of SPD techniques is their capability for producing bulk UFG materials not only free of porosity but also in dimensions suitable for structural applications.

In the last decade, the processing of UFG materials via SPD techniques has received considerable attention from the materials science community. Many research groups have started to work in this exciting field and the annual number of publications has increased exponentially. The Second International Symposium on Ultrafine Grained Materials provides a forum to examine all aspects of the science and technology of UFG materials produced by SPD techniques. This proceedings book includes papers dealing with recent progress in processing and microstructures, microstructural evolution, mechanical and physical properties, superplasticity, computational and analytical modeling, new SPD technologies, etc.

The editors are grateful to all of the authors and presenters for making this symposium and this proceedings book a great success. Their responses to this symposium far surpassed the organizers’ expectations. The symposium incorporates ninety-three presenters from 15 countries so that this symposium is truly an international forum on UFG materials. Almost all of the papers presented at the symposium are included in these proceedings.

As suggested by the title of this symposium, ultrafine-grained materials will be a continuing theme in future TMS meetings. Future symposia will be held at regular TMS Spring meetings at approximately two-year intervals.

Finally, the editors thank the TMS staff, especially Mr. Stephen J. Kendall, for their considerable guidance and assistance during the preparations for this symposium and in the publication of this important proceedings book.

Yuntian T. ZhuMS G755Materials Science and Technology DivisionLos Alamos National LaboratoryLos Alamos, NM 87545, USAEmail: [email protected]

Terence G. LangdonDepartments of Aerospace & Mechanical Engineering and Materials ScienceUniversity of Southern CaliforniaLos Angeles, CA 90089, USAEmail: [email protected]

Rajiv S. MishraDepartment of Metallurgical EngineeringUniversity of MissouriRolla, MO 65409, USAEmail: [email protected]

S. Lee SemiatinAir Force Research LaboratoryMaterials & Manufacturing DirectorateWPAFB, OH 45433, USAEmail: [email protected]

Michael J. SaranOES, Inc.3715 Traynham RdCleveland, OH 44122, USAEmail: [email protected]

Terry C. LoweMetallicum LLC1207 Callejon AriasSanta Fe, NM 87501, USAEmail: [email protected]

I. Microstructural Evolution

HIGH STRAIN MONOTONIC DEFORMATION–STRUCTURE AND STRENGTH

Niels Hansen1, Xiaoxu Huang1, Darcy A. Hughes2

1Center for Fundamental Research: Metal Structures in Four Dimensions, Materials Research Department, Risø National Laboratory, DK-4000 Roskilde, Denmark

2Center for Materials and Engineering Sciences, Sandia National Laboratories Livermore, CA 94550, U.S.A.

Abstract

The microstructural evolution with increasing equivalent strain has been compared in samples deformed to large strain by rolling, torsion, accumulative roll bonding and high pressure torsion. In all cases the evolution follows the same pattern of grain subdivision on a finer and finer scale down to boundary spacings in the range 100 – 300 nm. In parallel the misorientation angle increases giving rise to structures with low and high angle boundaries being spatially mixed. Detailed characterization of the microstructural parameters forms the basis of a flow stress analysis based on grain boundary strengthening and dislocation strengthening being linearly additive. This analysis has been validated by examining six experiments, 3 on deformed specimens and 3 on nanocrystalline specimens.

Keywords: rolling, torsion, accumulative roll bonding, high pressure torsion, deformation microstructure, flow stress

Introduction

Many deformation processes are under development with a common goal to obtain metals and alloys with ultrafine microstructures and consequently high strength. Common to these processes is also the application of high strains which are introduced without significantly changing the sample dimensions during processing. However, ultrafine structures and high strength also characterize metals and alloys deformed by conventional processes. A comparison between “developing” and “established” processes is, therefore, appropriate. Such a comparison must include a qualitative and quantitative description of the structural evolution during processing based on structural parameters [1]. In the present paper such a comparison includes four processes: two representing established processes, rolling and torsion, and two representing developing processes, accumulative roll bonding (ARB) and high pressure torsion (HPT). These processes have been chosen as they represent two different strain paths. For the two rolling processes the strain path is equivalent to plane strain compression, while for torsion the strain path is equivalent to simple shear. The hydrostatic pressure for the HPT may or may not contribute to the plasticity of the process. The comparative analysis will include the microstructural evolution as a function of strain to equivalent strains in the range of 5–10 followed by an analysis of relationships between flow stress and structural parameters. Only deformation at low temperature is considered. The materials analyzed are medium to high stacking fault energy materials and alloys, especially aluminium, nickel and copper.