SKM 2023 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 28: Liquid and Amorphous Metals
MM 28.4: Vortrag
Mittwoch, 29. März 2023, 11:00–11:15, SCH A 118
Rejuvenation engineering in metallic glasses by complementary stress and structure modulation — •Daniel Şopu1,2, Florian Spieckermann3, Simon Fellner1, Christoph Gammer1, and Jürgen Eckert1,3 — 1Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, Austria — 2Institut für Materialwissenschaft, Technische Universität Darmstadt, Germany — 3Department of Materials Science, Chair of Material Physics, Montanuniversität Leoben, Austria
Residual stress engineering is very widely used in the design of new advanced lightweight materials. For metallic glasses the attention has been on structural changes and rejuvenation processes. Here, based on high energy scanning X-ray diffraction strain mapping, transmission electron microscopy (TEM) and microindentation we distinguish between structural and elastic fluctuations, the two key factors for the observed extreme rejuvenation in triaxial compression. TEM characterization shows that structural rejuvenation under room temperature deformation relates to shear-induced softening and dilatation (large volumetric strain). High energy scanning X-ray diffraction strain mapping reveals large elastic fluctuations in metallic glasses after deformation under triaxial compression. Microindentation hardness mapping hints to a competing hardening-softening mechanism after compression and further reveals the complementary effects of stress and structure modulation. Molecular dynamics simulations provide an atomistic understanding of the complex shear band activity in notched metallic glasses and the related fluctuations in the strain/stress heterogeneity.