Phase Stability of Al-containing High-Entropy Alloys: A Comparison Study Using Computational Thermodynamics

Long-term phase stability behaviour is critical to enable high-entropy alloy (HEA) applicability. This study uses computational thermodynamic calculations to analyse the reported experimental phase stability data of Al-containing HEAs. These HEA compositions mainly contain Al, Co, Cu, Fe, Mn, Ni and one or two refractory elements such as Cr, Nb, Ta, Ti and V. However, they are not dominated by multiple refractory elements. Appropriate higher order phase diagrams are made using Calphad (Calculation of Phase Diagram) method to analyse 111 experimental investigation data. We collected such data on HEA phases, applying a few criteria to ensure the reasonableness to compare with Calphad results, such as the synthesis route was a casting technique such as vacuum arc melting (VAM) or induction melting (IM), the minimum duration of heat treatment was 24 h, and the cooling was rapid.