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MM: Metall- und Materialphysik

MM 2: Symposium Severe Plastic Deformation I

MM 2.3: Fachvortrag

Montag, 27. März 2006, 11:45–12:15, IFW A

New Routes to obtain Massive Nanostructured Materials — •Gerhard Wilde — Forschungszentrum Karlsruhe, Institute of Nanotechnology, P.O.B. 3640, 76021 Karlsruhe, Germany

Synthesizing massive nanocrystalline materials that are free from residual porosity and free from contaminations of the interior interfaces still presents a challenge to basic research as well as to application-related processing efforts. Severe plastic deformation (SPD) processes have frequently been applied to synthesize massive ultrafine-(submicron)-grained or disk-shaped nanostructured pure metals and alloys. New opportunities might be based on combining different non-equilibrium processing routes sequentially such that an initially metastable state is continuously energized and successively driven farer away from thermodynamic equilibrium. One example is given by plastically deforming metallic glasses. Another way to obtain specimens, e.g. of pure metals with extremely small average grain sizes and with quantities in the gram range is given by repeated cold-rolling and folding. The microstructure evolution as well as the limits of this technique in comparison to conventional SPD methods will be discussed. Additionally, sequentially combining different processing pathways that are based on continuous strain energy input present new routes for nanostructure formation. The available permutations offer a wide range of options for tailoring the microstructure and the shape and quantity of the product nanostructure and, at the same time, present a wide field yet to be explored. The support of this work by the DFG is gratefully acknowledged.