|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Thermodynamic Applications, Optimizations and Simulations in High-Temperature Processes: An EPD Symposium in Honor of Christopher W. Bale's 70th Birthday
||NN-12: Thermodynamic and Ab-initio Investigations of the Os-Th and Os-Y Systems
||Aissam Hidoussi, Aissa Belgacem-Bouzida, Fiseha Tesfaye, Said Kardellass
|On-Site Speaker (Planned)
Thermodynamic optimization of Os-Th and Os-Y systems has been performed by means of the CALPHAD (CALculation of PHAse Diagram) method combined with first-principles calculations. Enthalpies of formation for the intermetallic compounds Os<sub>2</sub>Th, Os<sub>2</sub>Th<sub>3</sub>, Os<sub>3</sub>Th<sub>7</sub>, Os<sub>2</sub>Y, and OsY<sub>3</sub> were computed by ab-initio method based on density functional theory (DFT). Vibrational and electronic free energies were calculated to attain the thermodynamic data at T > 0 K for the compounds Os<sub>2</sub>Th, Os<sub>2</sub>Th<sub>3</sub>, Os<sub>2</sub>Y, and OsY<sub>3</sub>. The liquid phase was modeled with the Redlich-Kister polynomial and the five intermetallic compounds were described as stoichiometric phases. The Gibbs energy functions for individual phases in Os-Th and Os-Y systems were evaluated by considering the first-principles computed enthalpies of formation, vibrational and electronic entropies, and the experimental phase equilibria data. A set of self-consistent thermodynamic parameters for each system has been obtained; calculated results show a reasonable agreement with the available experimental data in the literature.
||Planned: TMS Journal: Metallurgical and Materials Transactions