Speaker
Description
The design of multicomponent hydrogen storage alloys requires a systematic understanding of configurational stability and structure–property relationships. In this study, a cluster expansion (CE) approach combined with density functional theory (DFT) calculations was employed to investigate the Ti–V–Mn alloy system within the AB₂-type Laves phase framework. The CE model, trained on a diverse set of configurations, yields a low cross-validation score (~2.8 meV/atom), indicating high predictive accuracy. The resulting convex hull identifies twelve ordered structures on the DFT ground-state line across the compositional space.
Although Ti₈V₉Mn₇ corresponds to the global minimum in formation energy, the Ti8V8Mn8 configuration was selected for detailed investigation due to its balanced atomic distribution and structural uniformity. Such compositional balance is expected to promote homogeneous hydrogen accommodation and reduce local stress concentrations, which are critical factors governing hydrogen-induced embrittlement in transition-metal alloys.
The calculated structural parameters confirm that Ti8V8Mn8 preserves the characteristic Laves phase geometry, indicating a stable and well-ordered lattice. Mechanical properties derived from first-principles elastic constants demonstrate that the alloy is mechanically stable and exhibits pronounced ductility, as indicated by a high Pugh ratio (B/G > 1.75). This combination of structural stability and ductile behaviour is essential for mitigating failure during hydrogen absorption and desorption processes.
These results demonstrate that cluster expansion provides an effective framework for guiding the selection of stable alloy configurations, while highlighting the importance of compositional balance in optimising hydrogen storage performance and resistance to embrittlement.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |