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MM: Fachverband Metall- und Materialphysik
MM 15: Computational Materials Modelling III - Bulk thermodynamics/ Phase Transitions I
MM 15.5: Vortrag
Montag, 31. März 2014, 17:00–17:15, IFW D
Ab initio based insights into structural transformations and the role of interfaces in Fe-C alloys — •Xie Zhang1,2, Tilmann Hickel1, Jörg Neugebauer1, Jutta Rogal2, and Ralf Drautz2 — 1Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany — 2Interdisciplinary Centre for Advanced Materials Simulation, Ruhr-Universität-Bochum, 44780 Bochum, Germany
Structural transformations in Fe-C alloys are decisive for the mechanical properties of various steels. We have combined first principles and the Solid State Nudged Elastic Band method to study the structural transformations in the Fe-C system and the role of interfaces in these processes. Our investigations revealed the occurrence of an intermediate structure, which can perfectly bridge austenite, ferrite and cementite. The formation of such a structure was found to be the result of an interfacial adaptive behavior to accommodate the misfit of lattice constants and the different magnetic states in both phases. These insights provide a detailed understanding on the origin of the complex structure of cementite and the formation mechanisms of complex microstructures such as pearlite and bainite in steels.