Berlin 2015 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 20: Liquid and Amorphous Metals III: Deformation of Metallic Glasses

MM 20.4: Vortrag

Dienstag, 17. März 2015, 11:00–11:15, H 0107

Crossover from random three-dimensional avalanches to correlated nano shear bands in metallic glasses — •Carlos Herrero-Gómez, Jon-Olaf Krisponeit, Sebastian Pitikaris, Karina E.Avila, Stefan Küchemann, Antje Krüger, and Konrad Samwer — University of Goettingen,Goettingen, Germany

Bulk metallic glasses respond with elastic and/or plastic deformation to applied mechanical stresses. Such deformation do not have a smooth dependence with the applied stress but take place via jerky jumps, which are often referred as Crackling Noise [1] . We report a statistical analysis of the crackling noise in metallic glasses for creep measurements. Such analysis shows the existence of a crossover which seems to indicate a change in the process of deformation [2]. Although the microscopic theory of deformation remains an open task, this crossover seems to indicate a transition in the plastic deformation behavior from the three-dimensional random activity of Shear Transformation Zones to a two-dimensional nano-shear band sliding. Financial support by the EU Marie Curie Grant 60780 within the VitriMetTech Initial Training Network is thankfully acknowledged.

[1] Dahmen, Karin Ben-Zion, Yehuda Uhl, Jonathan. Micromechanical Model for Deformation in Solids with Universal Predictions for Stress-Strain Curves and Slip Avalanches. Phs Rev Let.102,17, 175501 (2009)

[2] Krisponeit, J.O et al. Crossover from random three-dimensional avalanches to correlated nano shear bands in metallic glasses. Nat. Commun. 5:3616 ( 2014)