| About this Abstract |
| Meeting |
2018 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations
|
| Presentation Title |
First-principles Investigation of Thermodynamics and Precipitation Kinetics in Al-Sc Alloys |
| Author(s) |
Ankit Gupta, Bengue Tas Kavakbasi, Biswanath Dutta, Blazej Grabowski, Martin Peterlechner, Tilmann Hickel, Sergiy V. Divinski, Gerhard Wilde, J Neugebauer |
| On-Site Speaker (Planned) |
Ankit Gupta |
| Abstract Scope |
Al-Sc alloys are promising light-weight materials that possess excellent mechanical properties, which are largely governed by nano-sized coherent Al<SUB>3</SUB>Sc precipitates. In this work, we use <I>ab initio</I> based methods to investigate the thermodynamic and kinetic aspects governing their formation. To determine the accuracy of the free energies we benchmark our framework of finite-temperature density functional theory, containing the complete finite temperature excitation spectrum, against highly accurate calorimetric measurements. The approach reveals and cures the limitation of physical models such as Sommerfeld and Debye model at low temperatures. The binding energies and finite-temperature lattice expansion determine the precipitation kinetics, which is studied in terms of time-temperature-transformation (TTT) diagrams employing kinetic Monte-Carlo simulations. The high configurational entropy in solid solution is found to control the maximum precipitate size and the temperature of the fastest precipitate formation. These insights allow designing process routes to tailor the size of precipitates in Al-Sc alloys. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |