Mechanism of intrinsic diffusion in the core of screw dislocations in FCC metals – A molecular dynamics study
| Autor: | Siavash Soltani, Niaz Abdolrahim, Panthea Sepehrband |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science General Computer Science Condensed matter physics General Physics and Astronomy 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Thermal diffusivity 01 natural sciences Crystallographic defect Core (optical fiber) Computational Mathematics Molecular dynamics Mechanics of Materials Vacancy defect 0103 physical sciences Partial dislocations General Materials Science Dislocation Diffusion (business) 0210 nano-technology |
| Zdroj: | Computational Materials Science. 144:50-55 |
| ISSN: | 0927-0256 |
| DOI: | 10.1016/j.commatsci.2017.11.048 |
| Popis: | The mechanism of self-diffusion in the absence of any pre-existing point defects (intrinsic diffusion) along an a/2 〈1 1 0〉 screw dislocation in FCC metals is studied using molecular dynamics simulations. High diffusivity along the dislocation core at elevated temperatures is found to be due to the constriction of partial dislocations, where a vacancy-interstitial pair forms. The two point defects separate and start to migrate along the core, giving rise to diffusion. Formation energy for both vacancy and self-interstitial are found to be much lower on the constricted node of partial dislocations compared to other atomic sites, indicating the important role of the constriction in enhancing the diffusion. |
| Databáze: | OpenAIRE |
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