First-principles calculations of β″-Mg5Si6/α-Al interfaces

Y. Wang, Z. K. Liu, L. Q. Chen, C. Wolverton

Research output: Contribution to journalArticle

56 Scopus citations

Abstract

The metastable β″-Mg5Si6 phase is often the most effective hardening precipitate in Al-rich Al-Mg-Si alloys. Two important factors that control the precipitate morphology are the strain energy and the interfacial energy between the precipitate and the matrix. By means of a first-principles supercell approach and density functional theory calculations, we have studied the interfacial properties between β″-Mg5Si6 and α-Al. We carefully construct a large number of interfacial cells in order to elucidate preferred interfacial terminations and orientations, as well as atom alignment and intermixing across the interface. Each of the low-energy interfaces we found possesses two key attributes: a high number of Al-Si bonds across the interface, and a face-centered cubic topological alignment of atoms across those interfaces. Our first-principles results yield quantitative values for the interfacial energies, lattice mismatches and strain energies that can be used in future predictions of precipitate morphologies as a function of size.

Original languageEnglish (US)
Pages (from-to)5934-5947
Number of pages14
JournalActa Materialia
Volume55
Issue number17
DOIs
StatePublished - Oct 1 2007

All Science Journal Classification (ASJC) codes

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

Fingerprint Dive into the research topics of 'First-principles calculations of β″-Mg<sub>5</sub>Si<sub>6</sub>/α-Al interfaces'. Together they form a unique fingerprint.

  • Cite this