Revealing the Selection of σ and μ Phases in CoCrFeNiMox High Entropy Alloys by CALPHAD

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Original languageEnglish
Pages (from-to)446-453
Journal / PublicationJournal of Phase Equilibria and Diffusion
Issue number4
Online published18 Jul 2018
Publication statusPublished - Aug 2018
Externally publishedYes


Though the strengthening effect of σ and μ phases in CoCrFeNiMox high entropy alloys has been confirmed, the selection of these two phases remains unclear, which restricts the further strengthening design. In this study, microstructures and phase compositions of CoCrFeNiMox (x = 0.1, 0.2, 0.3, 0.4, and 0.5) alloys were investigated through annealing at 600, 750, 900, 1000 °C for 7 days and 1080 °C for 3 days, respectively. Based on the experiment results, a (CoCrFeNi)-Mo phase selection diagram was drawn and compared with the calculated isopleth phase diagram of (CoCrFeNi)-Mo. The results indicate that the selection of σ and μ phases depends on the content of Mo greatly. Due to the limited prediction of phase selection and transformation by the isopleth phase diagram of (CoCrFeNi)-Mo, we design a (CoFeNi)-Mo-Cr isothermal phase diagram to reveal the transformation between σ and μ phases and their selections.

Research Area(s)

  • CALPHAD, high entropy alloys, σ and μ phases