B2 phases and their defect structures: Part I. Ab initio enthalpy of formation and enthalpy of mixing in the Al-Ni-Pt-Ru system

Sara Prins, Raymundo Arroyave, Chao Jiang, Zi Kui Liu

Research output: Contribution to journalConference article

Abstract

The enthalpies of formation of the bcc phases in the Al-Ni-Pt-Ru system, particularly in the Al-Ru binary and Pt-Al-Ru ternary subsystems, were calculated by first principle methods. The enthalpies of formation for stoichiometric bcc-B2 phases have been calculated using both the GGA and LDA approximations, while the enthalpies of formation for B2 phases with large amounts of constitutional defects (both vacancies and anti-site atoms) were calculated using the Special Quasirandom Structures (SQS) approach. The enthalpies of mixing for the disordered bcc-A2 phases have also been calculated with SQS by mimicking the random bcc alloy with the local pair and multisite correlation functions. The calculated B2 lattice parameters for the different defect structures were compared with experimental results. These results are used as input values for the CALPHAD modified sublattice model to describe the A2/B2 phases with one Gibbs energy function.

Original languageEnglish (US)
Article numberS5.14
Pages (from-to)523-528
Number of pages6
JournalMaterials Research Society Symposium Proceedings
Volume842
StatePublished - Aug 26 2005
Event2004 MRS Fall Meeting - Boston, MA, United States
Duration: Nov 29 2004Dec 2 2004

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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