Solid-solution phase formation rules for high entropy alloys: A thermodynamic perspective

  • Samaneh Mamnooni 1
  • Ehsan Borhani 1
  • Hassan Heydari 2
  • 1 Department of New Science and Technology, Nanomaterials Group, Semnan University, Semnan, Iran
  • 2 Department of Materials and Metallurgical Engineering, Semnan University, Semnan, Iran


To save time and money before starting the production of a high entropy alloy (HEA), it is important to predict the possibility of HEA formation and the probable final microstructure using the solid solution phase formation thermodynamic rules. In this research, a step-by-step calculation of thermodynamic parameters is conducted to predict the possibility of formation and determine the final properties such as ∆Hmix­, ∆Smix, δr, δχ, Ω, VEC, and Tm for three Ni20Co20Cu15Fe20Mn25, Ni35Co20Cu5Fe5Mn35, and Ni5Co5Cu35Fe35Mn20 HEAs. Based on the obtained results, it is not possible to form a HEA with a solid solution structure for the Ni35Co20Cu5Fe5Mn35 and Ni5Co5Cu35Fe35Mn20 systems due to a low ∆Smix value of 11.28 J.mol-1.K-1. Based on the calculated values of ∆Hmix­, intermetallic compound formation and segregation are predicted for Ni35Co20Cu5Fe5Mn35 and Ni5Co5Cu35Fe35Mn20, respectively.


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Keywords: High entropy alloy, Thermodynamic parameters, Solid solution, Phase formation, Segregation, Intermetallic compound


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Solid-solution phase formation rules for high entropy alloys: A thermodynamic perspective
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Mamnooni, S., Borhani, E., & Heydari, H. (2024). Solid-solution phase formation rules for high entropy alloys: A thermodynamic perspective. Synthesis and Sintering, 4(1), 65-78.

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