Closed and open-ended stacking fault tetrahedra formation along the interfaces of Cu-Al nanolayered metals

Ruizhi Li, Huck Beng Chew

Research output: Contribution to journalArticlepeer-review

Abstract

Stacking fault tetrahedra (SFTs) are volume defects that typically form by the clustering of vacancies in face-centred cubic (FCC) metals. Here, we report a dislocation-based mechanism of SFT formation initiated from the semi-coherent interfaces of Cu-Al nanoscale multilayered metals subjected to out-of-plane tension. Our molecular dynamics simulations show that Shockley partials are first emitted into the Cu interlayers from the dissociated misfit dislocations along the Cu-Al interface and interact to form SFTs above the triangular intrinsic stacking faults along the interface. Under further deformation, Shockley partials are also emitted into the Al interlayers and interact to form SFTs above the triangular FCC planes along the interface. The resulting dislocation structure comprises closed SFTs within the Cu interlayers which are tied across the Cu-Al interfaces to open-ended SFTs within the Al interlayers. This unique plastic deformation mechanism results in considerable strain hardening of the Cu-Al nanolayered metal, which achieves its highest tensile strength at a critical interlayer thickness of ~4 nm corresponding to the highest possible density of complete SFTs within the nanolayer structure.

Original languageEnglish (US)
Pages (from-to)2747-2763
Number of pages17
JournalPhilosophical Magazine
Volume95
Issue number25
DOIs
StatePublished - Sep 2 2015

Keywords

  • dislocation
  • molecular dynamics
  • nanolayered metals
  • plasticity
  • stacking fault tetrahedra

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Closed and open-ended stacking fault tetrahedra formation along the interfaces of Cu-Al nanolayered metals'. Together they form a unique fingerprint.

Cite this