Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 41: Electron Microscopy
MM 41.2: Vortrag
Mittwoch, 18. März 2015, 16:00–16:15, TC 006
Effect of severe plastic deformation on Al3Sc precipitation in an Al-Mg-Mn-Sc alloy — •Yulia Buranova1, Anna Mogucheva2, Harald Rösner1, Ankit Gupta3, Tilmann Hickel3, Sergiy V. Divinski1, and Gerhard Wilde1 — 1Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str.10, 48149 Münster, Germany — 2Belgorod State University, 85 Pobedy, 308015 Belgorod, Russia — 3Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany
Aluminum alloys containing scandium show excellent mechanical properties due to the presence of Al3Sc precipitates. In this study the effect of severe plastic deformation using equal channel angular pressing (ECAP) on the formation of Al3Sc precipitates has been investigated. The grain size, dislocation density, particles size, chemistry and particle distribution were investigated by analytical transmission electron microscopy. Additionally, geometric phase analysis (GPA) was applied to map local strains. The chemical mapping reveals a uniform distribution of Mg in the Al matrix. Three types of precipitates are generally found. The smallest particles, mostly Al3Sc, are coherent with sizes of 5-10 nm. Precipitates around 15-30 nm are found to contain Al, Mg, Mn and Sc. Larger particles contain mainly Al and Mn. These chemical trends are compared with ab initio calculations. While the middle- and large-size precipitates are predominantly found along grain boundaries and dislocation lines in their initial state, the ECAP processing produces an almost uniform distribution of particles. The experimental findings are compared with predictions based on atomistic simulations.