Structure and energetics of the coherent interface between the θ′ precipitate phase and aluminium in Al-Cu

Laure Bourgeois, Christian Dwyer, Matthew Weyland, Jian Feng Nie, Barrington C. Muddle

Research output: Contribution to journalArticle

88 Scopus citations

Abstract

The θ′ phase is a well-known intermediate phase that forms as part of the classic decomposition sequence of an aluminium-copper solid solution. It is also the archetypal precipitate phase of high-strength aluminium alloys. Here we use atomic-resolution electron microscopy imaging to reveal that the coherent interface of θ′ with aluminium can adopt a structure that differs from that previously assumed based on the bulk crystal structures. These observations, combined with first-principles energetics calculations for realistic models of embedded θ′ precipitates, show that this new interfacial structure constitutes an intermediate state in the atomistics of precipitate thickening. These findings will require revision of theoretical models of θ′ precipitate growth and nucleation.

Original languageEnglish (US)
Pages (from-to)7043-7050
Number of pages8
JournalActa Materialia
Volume59
Issue number18
DOIs
StatePublished - Oct 1 2011

Keywords

  • Aluminium alloys
  • Density functional theory
  • Interface structure
  • Precipitation
  • Scanning transmission electron microscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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