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MM: Fachverband Metall- und Materialphysik

MM 4: Liquid and Amorphous Metals I

MM 4.3: Talk

Monday, March 14, 2011, 11:30–11:45, IFW D

Inhomogeneous deformartion of metallic glasses — •Stefan Küchemann, Dennis Bedorf, Walter Arnold, and Konrad Samwer — 1. Physikalisches Institut, Universität Göttingen, Germany

Despite recent progress it is still not clear how local rearrangements take place in bulk metallic glasses under external stress. Previous results show that homogeneous deformation can be separated into reversible and irreversible processes which can be interpreted in the potential energy landscape picture.[1]

In the experiments reported in this contribution, we investigated anelasticity in bulk metallic glasses with nominal composition Pd₄₀Ni₄₀P₂₀. To modify the potential energy state, structurally relaxed samples were deformed at room temperature. The stresses cover the range from elastic response to inhomogeneous flow. In DSC measurements we found that the heat flow below T_G showed a clear indication for a strain dependence. Thus a certain amount of energy could be stored and is thermally relaxed below T_G.

Financial support by the DFG SFB 602 and the Leibniz-Program is thankfully acknowledged.

[1] J. S. Harmon, M. D. Demetriou, W. L. Johnson, K. Samwer, Anelastic to Plastic Transition in Metallic Glass Forming-Liquids, Phys. Rev. Lett. 99, 135502 (2007)