Dresden 2014 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 18: Poster Session

MM 18.38: Poster

Montag, 31. März 2014, 18:00–20:00, P4

Hardness measurements of shear bands in the bulk metallic glass Pd₄₀Ni₄₀P₂₀ by Nanoindentation — •Niklas Nollmann, Jörn Leuthold, and Gerhard Wilde — WWU Münster, Deutschland

In metallic glasses the hardness is influenced by the deformation state of the glass. For example in a sample deformed by rolling, the hardness is lower than in an undeformed sample. During the process of deformation the stress is localized in shear bands that are expected to have lower elastic modulus and lower hardness. In order to experimentally assess this hypothesis, nanoindentation was utilized. There for we prepared cold rolled metallic glass samples to obtain a defined state. Shear bands are produced, which are easy visible on the polished surface of the Sample. The hardness has been measured by two different ways. Firstly we made a number of defined nanoindents directly on top of the shear bands without polishing the sample. Secondly the sample has been polished before the nanoindentation measurements. SEM micrographs were taken before the polishing and finally after the nanoindentation process. By image correlation of these SEM micrographs, the position of the shear bands could be determined. The hardness of every indent was calculated in order to estimate the hardness of the shear bands.