Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1600368 | Intermetallics | 2012 | 8 Pages |
Previous work on the stability of the solid solution phases in the high entropy alloys is inconclusive. We used a series of thermo-mechanical treatments to study the stability of the solid solution phases in a high-entropy Al0.5CoCrCuFeNi alloy. The solid solution phases were found to be stable, against the intermetallic compounds, at high temperatures >850 °C and at low temperatures <300 °C. At intermediate temperatures, however, the intermetallic σ-phase co-existed with the solid solution phases. The experimental observations were verified by the thermodynamic calculation results. The mechanisms for the phase stability, both at equilibrium and after quenching-equivalent annealing treatments, were discussed, and the roles of high entropy and slow diffusion kinetics were highlighted.
► Phases in the as-cast HEAs are not the equilibrium phases at the room temperature. ► The sluggish diffusion kinetics in HEAs slows down the phase transformation. ► The high entropy favors the stability of solid solutions at elevated temperatures.