Berlin 2012 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 23: Topical Session Bulk Nanostrucured Materials V - Microstructure and Characterization III

MM 23.3: Talk

Tuesday, March 27, 2012, 12:00–12:15, H 0107

Following deformation mechanisms in nanocrystalline Ni and PdAu using diffraction techniques — •Patric Gruber¹, Jochen Lohmiller¹, Oliver Kraft¹, Christian Braun², Manuel Grewer², Rainer Birringer², Kerstin Schüler², Aaron Kobler³, Christian Kübel³, and Veijo Honkimäki⁴ — ¹KIT, Institute for Applied Materials, Karlsruhe — ²Universität des Saarlandes, Saarbrücken — ³KIT, Institute of Nanotechnology, Karlsruhe — ⁴ESRF, Grenoble, France

The contribution of specific deformation mechanisms which have been proposed for nanocrystalline (nc) materials is still under heavy debate. In situ characterization is necessary in order to (i) detect reversible mechanisms and (ii) ascribe the active mechanism to the respective strain regime. Therefore in situ compression tests are conducted on nc Ni and PdAu specimens using high energy synchrotron X-ray diffraction (XRD). Alloying of Au to Pd is expected to strongly influence the different deformation mechanisms of nc Pd and consequently give new insight in the predominant deformation mechanisms of nc materials in general. Based on the in situ experiments the deformation behavior of nc Ni and PdAu can be determined to be a distinct sequence of elastic grain interaction, grain boundary sliding, grain rotation, dislocation activity and grain growth. The succession of the different deformation mechanisms leads to a specific in-plane texture which could be determined for the first time. The specific differences in deformation behavior for Ni and PdAu alloys with varying Au content will be discussed.