Messerschmidt Dislocation Dynamics During Plastic Deformation

1. Auflage 2010
ISBN: 978-3-642-03177-9
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 129, 503 Seiten, eBook

Reihe: Springer Series in Materials Science

Along with numerous illustrative examples, this text provides an overview of the dynamic behavior of dislocations and its relation to plastic deformation. It introduces the general properties of dislocations and treats the dislocation dynamics in some detail.

Zielgruppe

Research

Autoren/Hrsg.

Messerschmidt, Ulrich

Inhaltsverzeichnis

General Properties of Dislocation Motion.- Experimental Methods.- Properties of Dislocations.- Dislocation Motion.- Dislocation Kinetics, Work-Hardening, and Recovery.- Dislocation Motion in Particular Materials.- Semiconductors.- Ceramic Single Crystals.- Metallic Alloys.- Intermetallic Alloys.- Quasicrystals.- Conclusion.

Leseproben

"Part I General Properties of Dislocation Motion (p. 2-4)

1 Introduction

The properties of crystalline solids can be classified into two groups. To the first one belong, for example, the elastic properties or the occurrence of X-ray diffraction patterns. These phenomena are controlled by the regular periodic structure of the crystal lattice. The second group involves properties like diffusion or the mechanical strength. Though these phenomena are also influenced by the regular crystal structure and its binding properties, they are essentially controlled by the defects in the regular arrangement of the atoms and may be called structure sensitive properties, as was introduced by Smekal [1].

The crystal defects are classified according to their extension in space into zero, one, two, and three-dimensional defects. Zero-dimensional defects or point defects include single missing atoms called vacancies, interstitial atoms, and substitutionally or interstitially incorporated foreign atoms like impurities. One-dimensional defects occur if the regular coordination of atoms is disturbed along a line.

These defects are called dislocations being the topic of this book. Two-dimensional defects are grain and phase boundaries while three-dimensional ones are larger precipitates or inclusions. Since the movement of dislocations is influenced by all types of defects, it turns out to be a very complex process. In the following section, it is shown that shearing a crystalline solid along a plane as a whole requires a high stress, which exceeds the measured strengths of materials by several orders of magnitude. Afterwards, in Sect. 1.2, dislocations are introduced.

Their motion through the crystal lattice allows the shearing in small steps, yielding realistic values of the mechanical strength. Part I of the book treats the general features of the dynamic dislocation behavior. At first, an outline of the experimental methods is given in Chap. 2. As a basis for understanding the dynamics, the geometric and elastic dislocation properties as well as the structure of dislocations in real crystals are reviewed in Chap. 3 before the dislocation motion itself is treated in Chap. 4.

Chapter 5 is concerned with the kinetic processes of dislocation generation, immobilization and annihilation. Part II is devoted to the dislocation motion in particular material classes, that is, to semiconductors in Chap. 6, ceramic single crystals (Chap. 7), metals (Chap. 8), intermetallic alloys (Chap. 9), and finally to quasicrystals (Chap. 10). In these chapters, particular dislocation processes are discussed in more detail and, whenever possible, they are illustrated by video sequences."