About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Advances in Titanium Technology
|
Presentation Title |
Twin Interface Structures and Fault-energetics in HCP Materials |
Author(s) |
Gorkem Gengor, Ahmed Sameer Khan Mohammed, Huseyin Sehitoglu |
On-Site Speaker (Planned) |
Gorkem Gengor |
Abstract Scope |
Twinning is a prominent deformation-mode in Hexagonal-Close-Packed (HCP) materials. Knowledge of energy-barriers of nucleation and migration is essential to predict twinning-onset and consequent mechanical-response. This study calculates energy-barriers for {101 ̅2} and {112 ̅1} twins in HCP materials such as Ti. These barriers have remained elusive due to ambiguity in understanding of the structure and twinning mechanism, caused by the complex crystallography of these planes. The equilibrium Twin-Boundary (TB) structure is established by defining and determining a lattice-offset through ab-initio Density Functional Theory (DFT) calculations. The lattice-offset specifies the relative position of twin- and matrix-phase lattices, and the offset minimizing the TB-energy is established. This offset leads to determination of the twinning-mechanism clarifying the shear-shuffle partition. The determined mechanism informs the calculation of the Generalized Planar Fault Energy (GPFE) landscape. To the best of our knowledge, the GPFE for these modes is calculated for the first time in literature. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Computational Materials Science & Engineering, Titanium |