Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 20: Computational Materials Modelling - Defect structure and formation
MM 20.3: Vortrag
Montag, 20. März 2017, 17:30–17:45, IFW B
Embedded-atom study of low-energy equilibrium triple junction structures and energies — •Sebastian Eich and Guido Schmitz — Institut für Materialwissenschaft, Universität Stuttgart
We present an atomistic study of the structures and defect energies of iron triple junctions (TJs) in polycrystalline materials. Line energies of bulk TJs (merging three grain boundaries (GBs)) and surface TJs (merging one grain boundary and two surfaces) are found to be very low. In absolute value, they amount to only a few 10−10 Jm−1. Remarkably, defined as a correct excess energy relative to the GBs, the bulk TJ energy is determined to be negative in all studied configurations with an average value of −2.8× 10−10 Jm−1. These quantitative results are in contrast to various experimental attempts, but they fully agree with simple geometric estimates.
Finally, we relate the negative TJ line energies to the excess segregation at TJs in a realistic Fe–Cr model system.
[1]: S. Eich, G. Schmitz, Embedded-atom study of low-energy equilibrium triple junction structures and energies, Acta Mater. 109 (2016) 364–374.
[2]: S. Eich, D. Beinke, G. Schmitz, Embedded-atom potential for an accurate thermodynamic description of the iron–chromium system, Comput. Mater. Sci. 104 (2015) 185–192.