Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 41: Interfaces II
MM 41.3: Vortrag
Donnerstag, 26. März 2009, 12:15–12:30, IFW D
Ginzburg-Landau theory of grain boundary premelting — •Robert Spatschek1,2 and Alain Karma2 — 1ICAMS, Ruhr-Universität Bochum — 2Northeastern University Boston
Grain boundary premelting is a phenomenon that emerges from repulsive forces between two differently oriented grains in a polycrystal. Typically, different types of forces contribute to the interaction, but it turns out that in metallic systems often “structural forces” play the dominant role. They are the consequence of lattice incompatibiliies due to a misorientation or grain shifts, and provoke elastic deformations and the formation of dislocations.
Starting from the classical density functional theory or a phase field crystal model we develop amplitude equations to shed light on the forces between solid-melt interfaces on an analytical and numerical level. We find in particular that these forces are significantly shorter ranged than previously anticipated and predict a grain boundary premelting transition for bcc iron.