Abstract
Previous density functional theory (DFT) studies of the 1/3 〈12̄10〉 screw dislocation in titanium have shown metastable core structures depending on the initial position of the dislocation line. We investigate this problem by modeling a screw dislocation with two initial positions using both DFT and a modified embedded atom (MEAM) potential for Ti with flexible boundary conditions. Both DFT and MEAM produce initial-position-dependent core structures. The MEAM potential stacking fault energies and core structures are in good agreement with DFT. MEAM potential computes the core energies and shows the behavior of both cores under applied strain. We found that the higher-energy core always reconstructs into the lower-energy one independent of the applied strain direction. Transformation from low- to high-energy core was not observed. Therefore, at T = 0 K, only the low-energy core is stable under applied strain.
Original language | English (US) |
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Pages (from-to) | 1287-1292 |
Number of pages | 6 |
Journal | Acta Materialia |
Volume | 60 |
Issue number | 3 |
DOIs | |
State | Published - Feb 2012 |
Keywords
- Core structure
- Density functional theory
- Dislocations
- Plastic deformation
- Titanium
ASJC Scopus subject areas
- Ceramics and Composites
- Metals and Alloys
- Polymers and Plastics
- Electronic, Optical and Magnetic Materials