Predicting β′ precipitate morphology and evolution in Mg-RE alloys using a combination of first-principles calculations and phase-field modeling

Y. Z. Ji*, A. Issa, T. W. Heo, J. E. Saal, C. Wolverton, L. Q. Chen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

111 Scopus citations

Abstract

The precipitate morphology in Mg-rare earth (RE) element binary alloys is predicted using a multi-scale modeling approach combining a three-dimensional (3-D) phase-field model and first-principles density functional theory calculations. First-principles calculations provide all the required input parameters for the phase-field model, including lattice parameters, elastic constants, formation energies and interfacial energies. This integrated model is applied to a Mg-Nd alloy as a model system. Quantitative 3-D phase-field simulations are performed to study the metastable β′ precipitate morphologies, habit plane formation and spatial distribution of the precipitates during isothermal aging. The predicted morphologies of β′ precipitates are in excellent agreement with existing experimental observations. The influence of the precipitate morphology on the mechanical properties is also evaluated using the Orowan equation. The results are expected to provide guidance for achieving desirable precipitate morphologies and thus mechanical properties in Mg alloys.

Original languageEnglish (US)
Pages (from-to)259-271
Number of pages13
JournalActa Materialia
Volume76
DOIs
StatePublished - Sep 1 2014

Funding

Y.Z.J. and L.-Q.Chen acknowledge the financial support by the Center for Computational Materials Design (CCMD), a joint National Science Foundation (NSF) Industry/University Cooperative Research Center at Penn State (IIP-1034965) and Georgia Tech (IIP-1034968) and a generous University Research Project by Ford Motor Company. A.I. and C.W. gratefully acknowledge the support of the Ford-Boeing-Northwestern alliance, award no. 81132882. J.E.S. was supported by the US Department of Energy, Office of Basic Energy Sciences through grant DE-FG02-98ER45721.

Keywords

  • First-principles calculation
  • Magnesium alloys
  • Phase-field modeling
  • Precipitate hardening effect
  • Precipitate morphology

ASJC Scopus subject areas

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

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