Equilibrium high entropy alloy phase stability from experiments and thermodynamic modeling

• DOI: 10.1016/j.scriptamat.2017.10.027
• Publication Date: 2017-10-29T10:45:13Z
• Authors: James E. Saal; Ida S. Berglund; Jason T. Sebastian; Peter K. Liaw; Greg B. Olson
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract Long-term stability of high entropy alloys (HEAs) is a critical consideration for the design and practical application of HEAs. It has long been assumed that many HEAs are a kinetically-stabilized metastable structure, and recent experiments have confirmed this hypothesis by observing HEA decomposition after long-term equilibration. In the present work, we demonstrate the use of the CALculation of PHAse Diagrams (CALPHAD) approach to predict HEA stability and processing parameters, comparing experimental long-term annealing observations to CALPHAD phase diagrams from a commercially-available HEA database. We find good agreement between single- and multi-phase predictions and experiments.