In geology and materials science, a deformation mechanism is a process occurring at a microscopic scale that is responsible for deformation: changes in a material's internal structure, shape and volume. The process involves planar discontinuity and/or displacement of atoms from their original position within a crystal lattice structure. These small changes are preserved in various microstructures of materials such as rocks, metals and plastics, and can be studied in depth using optical or digital microscopy.
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In this Dossier
- ⭐ Core Definition: Deformation mechanism
- Deformation mechanism in the context of Pressure solution
- Deformation mechanism in the context of Dislocation creep
Deformation mechanism in the context of Pressure solution
In structural geology and diagenesis, pressure solution or pressure dissolution is a deformation mechanism that involves the dissolution of minerals at grain-to-grain contacts into an aqueous pore fluid in areas of relatively high stress and either deposition in regions of relatively low stress within the same rock or their complete removal from the rock within the fluid. It is an example of diffusive mass transfer.
The detailed kinetics of the process was reviewed by Rutter (1976), and since then such kinetics has been used inmany applications in earth sciences.
View the full Wikipedia page for Pressure solutionDeformation mechanism in the context of Dislocation creep
Dislocation creep is a deformation mechanism in crystalline materials. Dislocation creep involves the movement of dislocations through the crystal lattice of the material, in contrast to diffusion creep, in which diffusion (of vacancies) is the dominant creep mechanism. It causes plastic deformation of the individual crystals, and thus the material itself.
Dislocation creep is highly sensitive to the differential stress on the material. At low temperatures, it is the dominant deformation mechanism in most crystalline materials. Some of the mechanisms described below are speculative, and either cannot be or have not been verified by experimental microstructural observation.
View the full Wikipedia page for Dislocation creep