ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Point-defect interactions of boron in α-Fe

Date: 27.03.2012
Time: 11:45 a.m.
Place: DPG Spring Meeting 2012, Berlin, Germany

Arthur Bialon
Thomas Hammerschmidt
Ralf Drautz

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.

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