SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 37: Topical Session: Defect Phases II
MM 37.4: Vortrag
Donnerstag, 30. März 2023, 11:15–11:30, SCH A 216
Ab-initio informed CALPHAD modelling of grain boundaries — •Tobias Spitaler1, Rishi Bodlos2, Daniel Scheiber2, and Lorenz Romaner1 — 1Montanuniversität Leoben, Department Werkstoffwissenschaft, Leoben, Österreich — 2Materials Center Leoben Forschung GmbH, Leoben, Österreich
The CALPHAD method is an important tool in material science to calculate phase diagrams and to predict phase stabilities of complex systems. Based on a model of the Gibbs Free energy of the bulk phases as function of composition, pressure and temperature the thermodynamic equilibrium quantities can be calculated with computer programs. In materials grain boundaries play an important role for mechanical properties and grain growth. Alloying elements often tend to segregate from or to the grain boundary, changing the properties of the grain boundary for example by weakening or strengthening the cohesion or by preventing grain boundary movement, which can lead to stabilisation of a nano-crystalline structure.
We therefore devise a formulation of the grain boundary Gibbs Free energy within the compound energy formalism with the goal to obtain the grain boundary state parameters such as composition and grain boundary area. We use DFT calculations to explore energy configurations of grain boundaries and couple them to thermodynamic models to investigate solute segregation and its impact on the grain boundary energy. With these results we can provide grain boundary phase diagrams and address thermodynamic nanocrystalline stability in metallic alloys.