Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 19: Computational Materials Modelling IV - Finite Temperature

MM 19.7: Vortrag

Dienstag, 27. März 2012, 11:45–12:00, TC 006

Point defect interactions of boron in α-Fe — •Arthur Bialon, Thomas Hammerschmidt, and Ralf Drautz — ICAMS, Ruhr Universität Bochum, Bochum, Germany

Modern steels are multicomponent systems that combine iron and carbon with further elements in order to achieve specific properties. The effect of boron additions depends on their spatial distribution that are affected not only by the fabrication process but also by interactions with other constituents. The latter may result in boron redistribution or the formation of boron-containing precipitates. In order to gain insight into the interaction of boron with point defects and impurities within the host matrix, we performed ab-initio calculations based on density functional theory for the case of α-Fe. We determined the distance-dependent interaction energies for different point defects, in particular a second boron atom, a vacancy and borons’ nearest neighbours in the periodic table: carbon, nitrogen and oxygen atoms. We observe that the interaction tendency is primarily determined by the position of boron, and virtually independent of the second point defect: substitutional boron binds the second point defect, while interstitial boron repels it.