Regensburg 2007 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 8: SYM Micro- and Nanomechanics II
MM 8.1: Talk
Monday, March 26, 2007, 14:45–15:15, H16
Superplastic deformation of ultrafine-grained Mg-alloys produced by micro-alloying and equal channel angular extrusion — •Florian H. Dalla Torre1, Anja Hänzi1, Maciej Krystian2, Peter J. Uggowitzer1, and Jörg F. Löffler1 — 1Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland — 2ARC Seibersdorf Research GmbH, Materials Research , Materials Micro-/Nanoengineering
The 'grain growth restriction'- concept via the addition of elements such as Zn, Ca, and Zr to Mg was used to cast and extrude two alloys with grain sizes of <5 and <10 micrometers, respectively. In combination with equal channel angular extrusion processing, the grain size was further reduced. Mechanical testing showed a substantial increase in ductility at room temperature compared to that in conventional Mg alloys. In addition, the high strain rate sensitivity, in combination with the effect of micro-alloying elements on stabilizing the grain size yields beneficial properties for superplastic micro- and net-shape-forming processes. The dependence of texture, grain size and twinning is discussed, together with their influence on temperature-dependent deformation mechanisms.