Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 45: Phase Transitions III
MM 45.2: Vortrag
Donnerstag, 26. März 2009, 15:30–15:45, IFW B
Crystal growth in metallic melts: A computer simulation study — •Roberto Rozas Cardenas and Jürgen Horbach — Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln
The crystal growth of Ni is studied using molecular dynamics computer simulation. The interactions between the particles are modeled by a potential of the embedded atom type. To this end, we consider the direct simulation of crystal growth through the movement of a planar solid-liquid interface at different temperatures. The kinetic growth coefficients and the melting temperature are estimated from an analysis of the interface growth velocity. The resulting melting temperature is at 1748 K, close to the experimental one at 1728 K. The crystal growth coefficient is about two orders of magnitude larger than in the intermetallic alloy Al50Ni50. We show that in the latter system crystal growth is driven by diffusion in the solid-liquid interface region, whereas for pure Ni phononic degrees of freedom lead to the much faster crystal growth kinetics.