Atomistic simulations of early stage clusters in Al–Mg alloys

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)484-492
Number of pages9
JournalActa Materialia
Volume166
Publication statusPublished - 1 Mar 2019
MoE publication typeA1 Journal article-refereed

Researchers

Research units

  • Norwegian University of Science and Technology
  • Tampere University

Abstract

The Cluster Expansion formalism based on Density Functional Theory (DFT) simulation data has been applied for Al–Mg alloys with high accuracy (∼1 meV/atom). The atomistic simulations are used to model the Al–Mg phase diagram, phase boundaries and the initial solute clustering at different compositions and temperatures. The obtained free energies of formation for the FCC, HCP and γ-phase are in accordance with the experimental phase diagram. The calculations demonstrate the formation of Guinier-Preston (GP) zones of Al3Mg (L12 phase) within the Al matrix under varying conditions. The computed transition temperatures where the ordered structures dissolve are approximately 50K higher than experimental data. The free energy barriers associated with the formation of GP-zones increase as the solute (Mg) concentrations are reduced and the temperature is increased.

    Research areas

  • Aluminium alloys, Atomistic modelling, Cluster expansion, Microstructure, Nucleation

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