Fulltext

Free-volume dependent pressure sensitivity of Zr-based bulk metallic glass

Dubach, Alban ; Eswar Prasad, K. ; Raghavan, Rejin ; Löffler, Jorg F. ; Michler, Johann ; Ramamurty, Upadrasta

In: Journal of Materials Research, 2009, vol. 24, no. 8, p. 2697-2704

Aggiungi alla tua lista
    Titre
    • Free-volume dependent pressure sensitivity of Zr-based bulk metallic glass
    Auteur
    • Dubach, Alban. Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland; and EMPA Materials Science and Technology, 3602 Thun, Switzerland
    • Eswar Prasad, K.. Department of Materials Engineering, Indian Institute of Science, Bangalore-560012, India
    • Raghavan, Rejin. EMPA Materials Science and Technology, 3602 Thun, Switzerland; and Department of Materials Engineering, Indian Institute of Science, Bangalore-560012, India
    • Löffler, Jorg F.. Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
    • Michler, Johann. EMPA Materials Science and Technology, 3602 Thun, Switzerland
    • Ramamurty, Upadrasta. Department of Materials Engineering, Indian Institute of Science, Bangalore-560012, India
    Type de document
    • Postprint
    Langue
    • Inglese
    Publié dans
    • Journal of Materials Research, 2009, vol. 24, no. 8, p. 2697-2704. Cambridge University Press
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:293594
    Summary
    Instrumented indentation experiments on a Zr-based bulk metallic glass (BMG) in as-cast, shot-peened and structurally relaxed conditions were conducted to examine the dependence of plastic deformation on its structural state. Results show significant differences in hardness, H, with structural relaxation increasing it and shot peening markedly reducing it, and slightly changed morphology of shear bands around the indents. This effect is in contrast to uniaxial compressive yield strength, σ y, which remains invariant with the change in the structural state of the alloys investigated. The plastic constraint factor, C = H/σ y, of the relaxed BMG increases compared with that of the as-cast glass, indicating enhanced pressure sensitivity upon annealing. In contrast, C of the shot-peened layer was found to be similar to that observed in crystalline metals, indicating that severe plastic deformation could eliminate pressure sensitivity. Microscopic origins for this result, in terms of shear transformation zones and free volume, are discussed