On the relationship between grain-boundary migration and grain-boundary diffusion by molecular-dynamics simulation
- Argonne National Lab., IL (United States). Materials Science Div.
A molecular-dynamics method for the simulation of the intrinsic migration behavior of individual, flat grain boundaries is presented. A constant driving force for grain-boundary migration is generated by imposing an anisotropic elastic strain on a bicrystal such that the elastic-energy densities in its two halves are different. For the model case of the large-planar-unit-cell, high-angle (001) twist boundary in Cu the authors demonstrate that the drift velocity is proportional to the applied driving force, thus enabling determination of the boundary mobility. The activation energy for grain-boundary migration is found to be distinctly lower than that for grain-boundary self-diffusion. A decrease in the related activation energies with increasing temperature is shown to arise from a crossover in the underlying mechanisms, from solid-like at low temperatures to liquid-like at high-temperatures that is accompanied by an underlying grain-boundary structural transition.
- Research Organization:
- Argonne National Lab., Materials Science Div., IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 665895
- Report Number(s):
- ANL/MSD/CP-96991; CONF-980744-; ON: DE98058042; TRN: AHC29819%%49
- Resource Relation:
- Conference: 9. international conference on intergranular and interphase boundaries in materials, Prague (Czech Republic), 6-9 Jul 1998; Other Information: PBD: Jul 1998
- Country of Publication:
- United States
- Language:
- English
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