Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 15: Poster Session

MM 15.59: Poster

Montag, 11. März 2013, 18:00–20:00, Poster E

Elastic-to-plastic transition: waiting time analysis of long term creep measurements — Jon-Olaf Krisponeit¹, Karina E. Avila², •Sebastian Pitikaris¹, Stefan Küchemann¹, Antje Krüger¹, and Konrad Samwer¹ — ¹I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen — ²Department of Physics and Astronomy, Ohio University, Athens, OH, 45701, USA

We studied the elastic-to-plastic transition of the bulk metallic glass Pd_77.5Cu₆Si_16.5 under uniaxially applied tensile stress. The crossover from initially elastic behavior via small plastic events to cooperative processes resulting in the emergence of macroscopic shear bands and even catastrophic failure is a very interesting phenomenon from both a materials science viewpoint and in fundamental physics. In theory, the statistic properties of avalanche-like slip events are studied intensively.

We recorded long term creep measurements (up to one week) under constant stress. Although single slip events–like activations of a shear transformation zone–are undetectable in macroscopic experiments, their cooperative avalanche-like motion is reflected in waiting time statistics. A numerical waiting time analysis was implemented and power-law behavior was found in the frequency distribution of waiting times. In addition, also power spectra have been analyzed. The results are discussed in terms of a transition from uncorrelated slip avalanches to the formation of shear bands.

We acknowledge financial support for this work by DFG via SFB 602 and FOR 1394.