About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Materials Genome, CALPHAD, and a Career over the Span of 20, 50, and 60 Years: An FMD/SMD Symposium in Honor of Zi-Kui Liu
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Presentation Title |
M-23: Electronic Origin of Phase Stability in Mg–Zn–Y Alloys with a Long-Period Stacking Order: A First-Principles Study |
Author(s) |
Takao Tsumuraya, Hiroyoshi Momida, Tamio Oguchi |
On-Site Speaker (Planned) |
Takao Tsumuraya |
Abstract Scope |
A dilute Mg-1Zn-2Y (at%) alloy exhibits a tensile yield strength of ∼600 MPa [1]. This strength is coupled with the appearance of a unique atomistic structure called long-period stacking order (LPSO). This study examines the origin of the phase stability of the 18R LPSO structure using first-principles density-functional theory calculations [2]. The heat of formation as a function of the number of Zn vacancies is calculated to evaluate the role of Zn atoms. The calculated convex hull indicates that the Zn atoms in LPSO are stable even at about half of the Y atoms. The partial density of states of Mg atoms nearest to the Zn atoms forms a valley structure due to the bonding state with Zn atoms, leading to the stability of the LPSO structure. [1] Y. Kawamura et al, Mater. Trans. 42 (2001) 1172. [2] T. Tsumuraya et al, Appl. Phys. Express, 15 (2022) 075506 (arXiv 2206.10873). |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Magnesium, Modeling and Simulation |