Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 29: Topical Session Bulk Nanostrucured Materials VI - Mechanical Properties I

MM 29.5: Vortrag

Mittwoch, 28. März 2012, 11:30–11:45, H 0107

Effects of alloying and temperature on the mechanical behavior of nanocrystalline Palladium alloys — •Ruth Schwaiger, Thomas Neithardt, and Oliver Kraft — Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM)

Over the past decade significant advances in understanding the deformation mechanisms in fine-grained metals and alloys have been made. It is now well accepted that in the grain size regime up to about 50 nm the dislocation activity is significantly reduced. Other deformation mechanisms such as nucleation and motion of partial dislocations, grain boundary sliding or grain rotation and grain boundary motion were shown to gain importance, which is corroborated by the small activation volumes and increased strain rate sensitivity typically observed in nanocrystalline metals. In our work, we investigated nanocrystalline Pd und PdAu-alloys using strain rate sensitive indentation and microcompression testing. In order to better understand the deformation mechanisms and their thermal activation, the experiments were conducted at different temperatures ranging from 10°C to 90°C. In this temperature range, no microstructural changes were observed. While the hardness was observed to increase with increasing alloying content, no significant alloying effect on the strain rate sensitivity and activation volume was observed at room temperature. For low alloying concentrations, the strain rate sensitivity and the apparent activation volume were observed to change with temperature.