Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 43: Liquid and Amorphous Metals II

MM 43.6: Vortrag

Donnerstag, 26. März 2009, 17:15–17:30, IFW A

Elastostatic preloading of bulk metallic glasses — •Denise Beitelschmidt¹, Sergio Scudino¹, Uta Kühn¹, and Jürgen Eckert^1,2 — ¹IFW Dresden, Institut für Komplexe Materialien, Helmholtzstrasse 20, D-01069 Dresden — ²TU Dresden, Institut für Werkstoffwissenschaft, D-01062 Dresden

Many bulk metallic glasses (BMG) show excellent elastic properties but their plastic behaviour is poor at room temperature. However recently, it has been reported that elastostatic compression below the yielding point can be used to enhance the plasticity of BMGs. In this work, the effect of preloading in the elastic regime on the structure and mechanical behaviour of different BMGs is investigated. Different alloys are tested with regard to their changing mechanical properties: as-cast and after preloading. Rods have been cast by different mould-casting techniques and were studied concerning their as-cast structural properties. Those as-cast samples have been preloaded for different periods and loads in the elastic regime and the effect on room-temperature plastic deformation has been investigated. Possible structure variation (e.g., SRO, atomic packing etc.) and creation of free volume as a result of preloading have been analyzed by XRD, DSC, density measurements and ultrasonic investigations. The results will be discussed with already published results from other groups to clarify the mechanisms of structural changes by preloading below yield strength.