|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XXI
||Ab Initio Interfacial Stability and Cu-segregation Effect upon η’ and η2 Precipitates in Al-Zn-Mg-Cu Alloys
||Yu-ning Chiu, Chung-yi Yu, Shih-kang Lin
|On-Site Speaker (Planned)
The benefit of Cu on the η-family strengthening precipitates in Al-Zn-Mg-Cu alloy has been well studied over the past decades. However, the role of Cu in the structure evolution during the transition from metastable η’ to stable η2 has yet to be understood clearly. As a result, the structures and energetics of η’ and η2 interface supercells in Al-Zn-Mg-Cu alloy were thoroughly investigated through ab initio calculations. The most feasible interface supercells with solute segregated in η’ and η2 were constructed, and with which, a comprehensive discussion on interfacial energy and strain energy as well as the atomic local strain hydrostatic invariant (ALSHI) were provided to plot the energy landscape for the transition with and without the consideration of Cu-segregation effect. Finally, an unreported mechanism of Cu-segregation was revealed, and based on which, a new strategy for the future optimal design of Al-Zn-Mg-Cu alloys was proposed.
||Aluminum, Phase Transformations, Computational Materials Science & Engineering