Regensburg 2010 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 34: Liquid and Amorphous Metals I
MM 34.1: Vortrag
Mittwoch, 24. März 2010, 10:15–10:30, H5
Structural Behavior of Cu-based Bulk Metallic Glasses under Compression — •Gang Wang1, Norbert Mattern1, Josef Bednarčik2, Simon Pauly1, JinMan Park1, Yue Zhang1, JunHee Han1, and Jürgen Eckert1,3 — 1Institute of complex materials, IFW-Dresden, 01069 Dresden, germany — 2HASYLAB at DESY, Notkestr. 85, D-22603 Hamburg, Germany — 3Institute of Materials Science, TU Dresden, D-01062 Dresden, Germany
The structural behavior of Cu-Zr binary bulk metallic glass (BMG) family under stress was investigated by means of in-situ high energy X-ray synchrotron diffraction. The components of the strain tensor were determined from the shifts of the maxima of the structure factor in reciprocal space as well by the atomic pair correlation function (PDF) in real space. The analysis of the PDF versus stress shows the occurrence of changes in short-range orders of the glass during elastic deformation. The number density of Cu-(Zr,Cu) and Zr-Zr nearest-neighbor atomic pairs becomes oriented along the loading direction. During plastic deformation the dominating volume fraction of the BMG exhibits the yield strain. The local deformation in shear bands can not be seen in the volume averaged PDFs. After unloading even in the plastically deformed state, the PDFs are identical to the as-cast state are within the error limits, which suggests that this anisotropic rearrangement of atoms under stress is a reversible process. The contribution of the plastically deformed regions localized within the shear bands are too low and therefore not visible in the diffraction patterns.