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 20.2: Vortrag

Dienstag, 17. März 2015, 10:30–10:45, H 0107

Avalanches dynamics and microstructure evolution of the glassy Cu50Zr50 system by means of Molecular Dynamic Simulations. — •Alexandra Lagogianni and Konrad Samwer — 1. Physikalisches Institut, Universität Göttingen, Germany

Several experimental studies revealed the presence of avalanches/stress drops in the plastic regime of BMGs, [1-3] upon mechanical deformation, and their direct correlation with the formation and arrest of single shear bands. Aiming to gain a deeper insight of this phenomenon on a smaller length scale we employed molecular dynamic simulations of an amorphous CuZr system under tension. Different strain rates were tested at room and glass transition temperature and the distribution of stress drops sizes were statistically analysed. In agreement with the experimental findings it came out that the serrated flow takes place even from the very beginning of the elastic region while the possible alterations that occur in the microstructure of the system were exhaustively studied. The present simulation results provide a theoritical confirmation of the experimental findings and a deeper and qualitative understanding of the origin of avalanches in a metallic glass.