The Plaston Concept: Plastic Deformation in Structural Materials

✍ Scribed by Isao Tanaka (editor), Nobuhiro Tsuji (editor), Haruyuki Inui (editor)

• Publisher: Springer
• Year: 2022
• Tongue: English
• Leaves: 278
• Category: Library

✦ Synopsis

This open access book presents the novel concept of plaston, which accounts for the high ductility or large plastic deformation of emerging high-performance structural materials, including bulk nanostructured metals, hetero-nanostructured materials, metallic glasses, intermetallics, and ceramics.The book describes simulation results of the collective atomic motion associated with plaston, by computational tools such as first-principle methods with predictive performance and large-scale atom-dynamics calculations. Multi-scale analyses with state-of-the art analytical tools nano/micro pillar deformation and nano-indentation experiments are also described. Finally, through collaborative efforts of experimental and computational work, examples of rational design and development of new structural materials are given, based on accurate understanding of deformation and fracture phenomena.This publication provides a valuable contribution to the field of structural materials research.

✦ Table of Contents

Preface
Contents
Part I Introduction
1 Proposing the Concept of Plaston and Strategy to Manage Both High Strength and Large Ductility in Advanced Structural Materials, on the Basis of Unique Mechanical Properties of Bulk Nanostructured Metals
1.1 Introduction
1.2 Reason of Strength-Ductility Trade-Off, and Mechanical Properties of Typical Bulk Nanostructured Metals
1.3 Bulk Nanostructured Metals Exhibiting Both High Strength and Large Ductility
1.4 Proposing the Concept of Plaston and a Strategy to Overcome Strength-Ductility Trade-Off
1.5 Conclusions
References
Part II Simulation of Plaston and Plaston Induced Phenomena
2 Free-energy-based Atomistic Study of Nucleation Kinetics and Thermodynamics of Defects in Metals; Plastic Strain Carrier ``Plaston''
2.1 Introduction
2.2 Shuffling Dominant {10bar12} langle10bar1bar1rangle Deformation Twinning in Hexagonal Close-Packed Magnesium (ch2Ishii16)
2.3 Dislocation Nucleation from GBs (ch2Junping16)
2.4 Homogeneous Dislocation Nucleation in Nanoindentation (ch2Sato19)
2.5 Summary
References
3 Atomistic Study of Disclinations in Nanostructured Metals
3.1 Introduction
3.1.1 Various Deformation Modes in Nanostructured Metals
3.1.2 Disclinations
3.2 Grain Subdivision: Disclinations in Grains
3.2.1 Strain Gradients in Severe Plastic Deformation Processes
3.2.2 Grain Subdivision by Severe Plastic Deformation
3.2.3 Partial Disclinations Induced by the Strain Gradient
3.3 Fracture Toughness: Disclinations at the Grain Boundary
3.3.1 High Strength and High Toughness
3.3.2 Dislocation Emission from the Grain Boundary
3.3.3 Intragranular Crack
3.3.4 Intergranular Crack
3.4 Conclusion
References
4 Collective Motion of Atoms in Metals by First Principles Calculations
4.1 Introduction
4.2 Phase-Transition Pathway in Metallic Elements
4.3 HCP-Ti Under Shear Deformation Along Twinning Mode
References
5 Descriptions of Dislocation via First Principles Calculations
5.1 Introduction
5.2 Stacking Fault Energy
5.3 Analytical Description of Dislocations: Peierls–Nabarro Model
5.4 First Principles Calculations of a Dislocation Core
5.4.1 Atomic Modeling of a Dislocation Core
5.4.2 First Principles Calculations
References
Part III Experimental Analyses of Plaston
6 Plaston—Elemental Deformation Process Involving Cooperative Atom Motion
6.1 Introduction
6.2 Nucleation and Motion of Plastons (Possible Deformation Modes) Under Stress
6.3 Cooperative Motion of Atoms in Plastons
6.4 Origin of Cooperative Atom Motion in the Nucleation of Plastons
6.5 Applications of the Concept of Plastons to the Improvement of Mechanical Properties of Structural Materials
6.6 Conclusions
References
7 TEM Characterization of Lattice Defects Associated with Deformation and Fracture in α-Al2O3
7.1 Introduction
7.2 Atomic Structure Analysis of Dislocations in Low-angle Boundaries
7.2.1 1/3<11bar2 0>Basal Edge Dislocation
7.2.2 1/3<11 bar2 0> Basal Screw Dislocation
7.2.3 <1bar1 00> Edge Dislocation
7.2.4 1/3 Mixed Dislocation
7.3 Analysis of Dislocation Formation and Grain Boundary Fracture by in Situ TEM Nanoindentation and Atomic-Resolution STEM
7.3.1 Introduction of a Basal Mixed Dislocation and Its Core Structure
7.3.2 Crack Propagation Along Zr-Doped ∑13 Grain Boundary
7.4 Summary
References
8 Nanomechanical Characterization of Metallic Materials
8.1 Nanomechanical Characterization as an Advanced Technique
8.2 Plasticity Initiation Analysis Through Nanoindentation Technique
8.3 Effect of Lattice Defects Including Grain Boundaries, Solid-Solution Elements, and Initial Dislocation Density on the Plasticity Initiation Behavior
8.3.1 Grain Boundary
8.3.2 Solid Solution Element
8.3.3 Initial Dislocation Density
8.4 Initiation and Subsequent Behavior of Plastic Deformation
8.4.1 Sample Size Effect and Elementary Process
8.4.2 Dislocation Mobility and Mechanical Behavior in Bcc Crystal Structures
8.4.3 Plasticity Induced by Phase Transformation
8.5 Summary
References
9 Synchrotron X-ray Study on Plaston in Metals
References
10 Microstructural Crack Tip Plasticity Controlling Small Fatigue Crack Growth
10.1 Introduction: Small Crack Problem
10.2 Grain Refinement: Characteristic Distributions of Dislocation Barrier and Source
10.3 Plasticity-Induced Transformation: Thermodynamic-Based Design
10.3.1 Geometrical Effect on Crack Tip Deformation
10.3.2 Transformation-Induced Hardening and Lattice Expansion
10.4 Dislocation Planarity: Stress Shielding and Mode II Crack Growth
10.5 Kinetic Effects of Solute Atoms on Crack Tip Plasticity
10.5.1 Strain-Age Hardening
10.5.2 Effects of i–s Interaction
10.6 Effect of Microstructural Hardness Heterogeneity: Discontinuous Crack Tip Plasticity
10.7 Summary
References
Part IV Design and Development of High Performance Structural Materials
11 Designing High-Mn Steels
11.1 Introduction
11.2 Plasticity Mechanisms in γ-austenite
11.3 Polyhedron Models for FCC Plasticity Mechanisms
11.4 Plasticity Mechanisms Under Tensile Loading
11.4.1 Selection Rule and Generation Processes
11.4.2 Transformation- and Twinning-Induced Plasticities
11.4.3 Martensite/twin Variants
11.5 Plasticity Mechanisms Under Cyclic Loading
11.6 Concluding Remarks
References
12 Design and Development of Novel Wrought Magnesium Alloys
12.1 Introduction
12.2 Requirements for Wrought Magnesium Alloys
12.2.1 Extruded Alloys
12.2.2 Sheet Alloys
12.3 Development of Industrially Viable Precipitation Hardenable Alloys
12.4 Examples of Heat-Treatable Wrought Alloys
12.4.1 Extruded Alloys
12.4.2 Sheet Alloys
12.4.3 Toward the Improvement of Room Temperature Formability
12.4.4 Strengthening by G.P. Zones
12.5 Summary and Future Outlooks
References