Dresden 2003 – wissenschaftliches Programm
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M: Metallphysik
M 37: Diffusion und Punktdefekte II
M 37.1: Vortrag
Donnerstag, 27. März 2003, 11:45–12:00, IFW B
Interdiffusion studied with a continuum mechanical and an atomistic model - a comparison — •M. Hartmann1, R. Weinkamer1, J. Svoboda2,3, F.D. Fischer4,3, and P. Fratzl1,3 — 1Erich Schmid Inst. of Materials Science, ÖAW and Montanuniv. Leoben, Austria — 2Inst. of Physics of Materials, Academy of Sciences of the Czech Republic, Brno — 3Materials Center Leoben GmbH, Austria — 4Inst. of Mechanics, Montanuniv. Leoben, Austria
Recently new experimental investigations of interdiffusion (including the well known Kirkendall effect) as well as new theoretical considerations of multicomponent diffusion, that include the off-diagonal elements of the Onsager matrix in the problem description [1], obtained results challenging common textbook knowledge. Motivated by these new developments we have performed Monte Carlo (MC) simulations to gain an atomistic insight into the problem of interdiffusion. Starting with the same initial conditions and the same diffusivities of the atoms, we compared the predictions of the continuum mechanical model and the results of the MC simulations. To be more specific, the concentration profiles, distribution of vacancies and the relation between the tracer diffusivities and the interdiffusion coefficient D were investigated in detail. Furthermore, since the behaviour of the vacancies is the key-experiment to test various theories of diffusion we verified the surprising predictions of the continuum model concerning the transient effects in the vacancy concentration profile at early times, assuming an initially homogenous vacancy distribution.
[1] J. Svoboda, et al., Acta Mater. 50, 1369 (2002).