About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
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Symposium
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Atomistic Simulations Linked to Experiments to Understand Mechanical Behavior: A MPMD Symposium in Honor of Professor Diana Farkas
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Presentation Title |
Experimental evidence and first-principles verification of the deformation behavior of basal twist grain boundaries in Ti |
Author(s) |
Biaobiao Yang, Samuel Hémery, Wei Shao, Victoria A. Tucker, Michael S. Titus, Miguel A. Monclús, Javier Llorca |
On-Site Speaker (Planned) |
Javier Llorca |
Abstract Scope |
Recent experimental evidence suggests that basal twist grain boundaries (BTGBs) are
responsible for the nucleation of fatigue cracks in Ti alloys. They are composed by two hcp α crystals rotated about the [0001] axis, and separated by a grain boundary parallel to (0001). The mechanical behavior of bicrystals containing BTGBs was characterized through micropillar compression tests and the deformation mechanisms were analyzed by means of high resolution scanning and transmission electron microscopy. Shear deformation occurred by the shear glide of one basal grain over the other basal grain at very low values of the critical resolved shear stress. In order to understand this mechanism, the generalized stacking fault energy (GSFE) of coincident site lattice BTGBs with different twist angles was determined through first principles calculations of supercells. It was found that the GSFE was negligible for all coincident site lattice BTGBs and explained the negligible slip resistance. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Titanium, Mechanical Properties |