Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 34: Poster session II

MM 34.18: Poster

Dienstag, 21. März 2017, 18:30–20:30, P4

Mechanical Analysis of Metallic Glasses in the Non-Linear Regime — •Clemens Garve, Birte Riechers, and Konrad Samwer — Georg-August-Universität Göttingen

Amorphous metals are used in various applications, however the strongly temperature dependent viscoelastic behavior under deformation is not fully explained yet. To gain more understanding we deform a Palladium-based metallic glass using oscillatory stresses with amplitudes sufficiently high to drive the system beyond the Hookian regime of linear response.

Following experimental approaches used in dielectric spectroscopy [1] an oscillating mechanical stress was applied, which was switched from a low to high stress amplitude and back using a dynamical mechanical analyzer. By using Fourier analysis, we were able to separate our data into nonlinear contributions at fundamental and higher harmonic frequencies. While deforming with high stresses and in the following low stress section, the nonlinear contributions show time-dependent behavior, which was characterized to extract the time-scale of structural recovery [2]. The temperature and stress dependence of nonlinear contributions regarding amplitude and timescale were investigated.

We acknowledge support by DFG Research Unit FOR1394.

Citations: [1] Huang and Richert. "Dynamics of glass-forming liquids..." J. Phys. Chem. 124.16 (2006) [2] Riechers, Samwer, and Richert. "Structural recovery in plastic crystals by time-resolved non-linear dielectric spectroscopy." J. Phys. Chem. 142.15 (2015)