Plasticity and crack extension in single-crystalline long-period stacking ordered structures of Mg85Zn6Y9 alloy under micro-bending

Research output: Contribution to journalArticlepeer-review

Authors

  • Yoji Mine
  • Ryo Maezono
  • Tsuyoshi Mayama
  • Jing Wu
  • Kazuki Takashima

Colleges, School and Institutes

External organisations

  • Kumamoto University
  • Kawasaki Heavy Industries, Ltd

Abstract

Micro-bending tests were performed on single-crystalline cantilever beams of long-period stacking ordered (LPSO) structures of Mg85Zn6Y9 alloy with and without a notch to study crystal plasticity and cracking behaviour under basal and non-basal slip conditions. The activation of basal slip induced load drops during the deformation of a plain cantilever beam with the bending moment perpendicular to the basal plane. A cantilever sample oriented for prismatic slip exhibited high yield stress and moderate strain hardening. The apparent critical resolved shear stress (CRSS) for prismatic slip was determined to be ∼360 MPa, significantly higher than 30 MPa CRSS determined for basal slip. A crystal plasticity finite element analysis of the micro-bending test on the sample oriented for prismatic slip was performed to verify the CRSS values determined. In addition, the intrinsic fracture resistance for crack growth along the <a> direction on a prismatic plane is higher than that for crack growth along the <a> direction on a basal plane. In combination, these results indicate that inhibition of basal slip activity contributes not only to high strength but also to high intrinsic toughness observed in this LPSO structure.

Details

Original languageEnglish
Pages (from-to)433-442
Number of pages10
JournalJournal of Alloys and Compounds
Volume718
Early online date22 May 2017
Publication statusPublished - 25 Sep 2017

Keywords

  • Anisotropy, Intermetallics, Mechanical properties, Metals and alloys, Transmission electron microscopy