About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Response of Materials Investigated through Novel In-situ Experiments and Modeling
|
| Presentation Title |
Core Structure and Mobility of <c+a> Dislocations in Alpha-Ti |
| Author(s) |
Satish I. Rao, Adam Pilchak, Christopher Woodward |
| On-Site Speaker (Planned) |
Satish I. Rao |
| Abstract Scope |
Toward a goal of understanding of fatigue crack propagation in alpha-Titanium alloys, the MEAM spline potential of Hennig et.al. was used to determine the planar fault energies on basal, prism, pyramidal planes and <a> screw dislocation core structure in pure alpha-Ti. It was found that the MEAM-spline potential gives fault energies and <a> screw dislocation core structure in fairly good agreement with first principles calculations. It has been used in this talk to determine the core structure and mobility of <c+a> dislocations in pure alpha-Ti. The minimum energy core structure for <c+a> screw dislocations is dissociated on the pyramidal 1 plane. At 300 and 600K, the screw dislocation moves by a regular Peierls mechanism with critical stresses of the order of 0.005G. The mixed dislocation with <100> line direction is climb dissociated on the basal plane. Such simulation results are compared with experimental yield stress data for pure alpha-Ti. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |