Regensburg 2007 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 8: SYM Micro- and Nanomechanics II

MM 8.2: Talk

Monday, March 26, 2007, 15:15–15:45, H16

Deformation Processing of Massive Nanostructured Materials — •Gerhard Wilde — Institut für Materialphysik, Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster

One way to obtain massive specimens, e.g. of pure fcc or hcp metals with extremely small average grain sizes is given by repeated cold-rolling, as shown recently for several pure metals. In fact, even intermetallic alloy phases with rather high melting temperatures could be processed successfully, such that a residual grain size of less than 100 nm was obtained. This new method extends the range of microstructures that are accessible by severe plastic deformation treatments towards smaller grain sizes. In contrast to nanocrystalline materials obtained by powder methods such as inert gas condensation, the material synthesized by cold rolling contains a high density of dislocations as well as significant residual strain in the nanosized grains. In addition, to synthesis, recent results related to the underlying deformation mechanisms of the nanocrystalline material containing lattice defects as well as new measurements of the mechanical properties hardness and strength in dependence of the grain size and will be discussed for pure fcc model systems. These first results indicate significant improvements concerning properties and performance that can be gained through nanostructuring by applying advanced deformation processing treatments. The ongoing work is supported by the Deutsche Forschungsgemeinschaft.