Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 66: Topical session: Dynamics, relaxation and deformation in deeply supercooled metallic liquids and glasses VI - mechanical properties

MM 66.1: Topical Talk

Donnerstag, 23. März 2017, 15:45–16:15, IFW A

Molecular Dynamics Simulation On The Avalanche Dynamics and the microstructural evolution in the so called elastic region of the Cu50Zr50 — •Alexandra Lagogianni, Marius Milnikel, and Konrad Samwer — I. Physikalisches Institut, Georg-August Universität Göttingen,Göttingen,Deutschland

We present results on the study of the avalanche dynamics of a 3D Cu50Zr50 system by means of molecular dynamics simulations. The system is subjected to a finite strain rate deformation scheme and to the athermal quasistatic protocol. We find that the avalanches occur from the beginning of the so called elastic region. The critical exponents obtained by the stress drop sizes and time duration distributions for the elastic and plastic region are similar, indicating that the difference in the deformation mechanisms that govern the two regions are not depicted in these kind of statistical profiles of the avalanches. The two regions differ in the way that the number of the avalanches, their average size and the instantaneous shear modulus evolves with strain. Additionally the stress drops are accompanied by the appearance of regions in the systems that undergo shear transformations and consist of characteristic categories of clusters. The percentage of the clusters in these regions evolves upon deformation in a correlated way with the stress and the energy of the system. The overall decrease/increase of their number upon deformation is taking place by a continuous structural loop where an initial type of cluster transforms into an intermediate one of the same coordination number and consecutively this new type transforms back again to the initial state.