Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 15: Poster Session

MM 15.1: Poster

Montag, 11. März 2013, 18:00–20:00, Poster E

Precipitate Formation in Fe-Cu Systems investigated by Computer Simulations — •Johannes Zeman¹, Kai Kratzer¹, David Molnar², and Axel Arnold¹ — ¹ICP, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany — ²IMWF, Universität Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany

At temperatures above 300^∘C, copper-alloyed bcc-iron relatively quickly shows the formation of copper nanoprecipitates strongly affecting its mechanical properties. We investigate the kinetics of this phase transition qualitatively and quantitatively, using a vacancy-based atomistic kinetic Monte-Carlo simulation [1]. At high supersaturations, we find that Ostwald ripening is the dominant process, while at low supersaturations, nucleation determines the overall time scale of the transition. The time-temperature- transformation analysis [2] on the whole range of temperatures therefore requires the combination of brute force simulations and forward flux rare event sampling [3]. Our simulations show good agreement with the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory.

[1] P. Binkele: Atomistische Modellierung und Computersimulation der Ostwald-Reifung von Ausscheidungen beim Einsatz von kupferhaltigen Stählen, PhD thesis, University of Stuttgart (2006)

[2] E. J. Mittemeijer: Fundamentals of Materials Science, p. 426, Springer, Heidelberg (2011)

[3] R. J. Allen, C. Valeriani, and P. Rein ten Wolde: Forward flux sampling for rare event simulations, J. Phys. Condens. Matter 21 (2009)