About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
2026 Technical Division Student Poster Contest
|
| Presentation Title |
SPG-21: Atomistic Mechanisms and Computational Design of Thermally Stable Nanoprecipitates in Al-Zn-Mg Alloys |
| Author(s) |
Yu-ning Chiu, Wei-ting Lin, Shih-kang Lin |
| On-Site Speaker (Planned) |
Yu-ning Chiu |
| Abstract Scope |
7000 series (Al-Zn-Mg) alloys derive their high strength from the metastable η' nanoprecipitates. However, thermal stability is limited as η' phases are prone to transforming into stable η phases. To stabilize η' nanoprecipitates, we systematically screened 21 candidate microalloying elements via high-throughput DFT calculations of solute segregation at the precipitate–matrix interface. Machine-learning analysis indicates that segregation potency correlates strongly with reduced coherency strain energy at the precipitate-matrix interface. Among the candidates, smaller-sized solutes such as Cu, Mn, and Ni are predicted to be effective segregants for enhancing η' stability. Experimentally, DSC measurements confirmed a ~30°C increase in the η'→η transition temperature for a developed Al-Zn-Mg-Ni alloy compared to commercial Al-Zn-Mg-Cu (AA7075) alloy. Mechanical testing further demonstrates that the Al-Zn-Mg-Ni alloy achieves comparable peak-aged strength while exhibiting improved strength retention after thermal exposure. These results provide a microalloying strategy for designing thermally stable, high-temperature 7000-series aluminum alloys. |
| Proceedings Inclusion? |
Undecided |
| Keywords |
Aluminum, Computational Materials Science & Engineering, Phase Transformations |