Abstract
Irradiation of metals with high-energy atomic particles creates obstacles to glide, such as voids, dislocation loops, stacking-fault tetrahedra and irradiation-induced precipitates through which dislocations have to move during plastic flow. Approximations based on the elasticity theory of defects offer the simplest treatment of strengthening, but are deficient in many respects. It is now widely recognised that a multiscale modelling approach should be used, wherein the mechanisms and strength parameters of interaction are derived by simulation of the atomic level to feed higher-level treatments based on continuum mechanics. Atomic-scale simulation has been developed to provide quantitative information on the influence of stress, strain rate and temperature. Recent results of modelling dislocations gliding under stress against obstacles in a variety of metals across a range of temperature are considered. The effects observed include cutting, absorbing and dragging obstacles. Simulations of 0 K provide for direct comparison with results from continuum mechanics, and although some processes can be represented within the continuum treatment of dislocations, others cannot.
Original language | English |
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Pages (from-to) | 353-361 |
Number of pages | 9 |
Journal | Materials Science and Engineering: A |
Volume | 400-401 |
Issue number | 1-2 SUPPL. |
DOIs | |
State | Published - Jul 25 2005 |
Funding
This research was sponsored by the Division of Materials Sciences and Engineering and the Office of Fusion Energy Sciences, U.S. Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. It was supported by a grant from the UK Engineering and Physical Science Research Council and a JREI grant of the Higher Education Funding Council for England.
Keywords
- Atomic-scale modelling
- Dislocations
- Radiation damage
- Yield stress