Book contents
- Frontmatter
- Contents
- Preface
- Part I General background
- Part II Materials science of deformation
- 4 Elasticity
- 5 Crystalline defects
- 6 Experimental techniques for study of plastic deformation
- 7 Brittle deformation, brittle–plastic and brittle–ductile transition
- 8 Diffusion and diffusional creep
- 9 Dislocation creep
- 10 Effects of pressure and water
- 11 Physical mechanisms of seismic wave attenuation
- 12 Deformation of multi-phase materials
- 13 Grain size
- 14 Lattice-preferred orientation
- 15 Effects of phase transformations
- 16 Stability and localization of deformation
- Part III Geological and geophysical applications
- References
- Materials index
- Subject index
- Plate section
5 - Crystalline defects
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Part I General background
- Part II Materials science of deformation
- 4 Elasticity
- 5 Crystalline defects
- 6 Experimental techniques for study of plastic deformation
- 7 Brittle deformation, brittle–plastic and brittle–ductile transition
- 8 Diffusion and diffusional creep
- 9 Dislocation creep
- 10 Effects of pressure and water
- 11 Physical mechanisms of seismic wave attenuation
- 12 Deformation of multi-phase materials
- 13 Grain size
- 14 Lattice-preferred orientation
- 15 Effects of phase transformations
- 16 Stability and localization of deformation
- Part III Geological and geophysical applications
- References
- Materials index
- Subject index
- Plate section
Summary
Crystalline defects such as point defects (vacancies, interstitial atoms, hydrogen-related defects etc.), dislocations and grain boundaries play essential roles in plastic deformation. This chapter gives a brief review of the fundamentals of crystalline defects. The relation between the concentration of point defects and temperature, pressure and chemical environment is discussed based on thermodynamic principles. Some basic properties of dislocations including the slip systems, dislocation energy and the important properties of grain boundaries and subgrain boundaries are summarized.
Key words point defects, dislocations, grain boundaries, subgrain boundaries, vacancies, interstitials, stoichiometry, ferric iron, slip systems, Burgers vector, Peach–Koehler force, Schmid factor.
Defects and plastic deformation general introduction
A crystalline material is made of a nearly perfect periodic array of atoms. When a force is applied, individual atoms move away from their stable positions. This will cause a restoring force. When the statistical fluctuation caused by atomic vibration is neglected and when deformation is homogeneous, then the (homogeneous) displacement of atoms due to a reasonable level of stress is so small that upon the removal of force, the atoms will return to their original positions, hence deformation is elastic. Plastic deformation occurs when atoms move to the next stable position, so that after the removal of external force they do not go back to their original positions.
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- Deformation of Earth MaterialsAn Introduction to the Rheology of Solid Earth, pp. 75 - 98Publisher: Cambridge University PressPrint publication year: 2008