Tailoring strength and ductility of high-entropy CrMnFeCoNi alloy by adding Al

High-entropy alloys with high strength and acceptable ductility at both room and elevated temperatures for high-temperature structural applications are desired. In this paper, CrMnFeCoNi alloy with outstanding ductility but low strength was selected as baseline alloy to study the formation of hard phase to strengthen this ductile alloy by adding Al into it. The results indicate that there is a phase structure transition from fcc to bcc when adding enough Al into CrMnFeCoNi. The yield strength and hardness increase with the content of Al increasing, due to the formation of hard bcc phase in the ductile CrMnFeCoNi alloy. The CrMnFeCoNiAl alloy with a bcc structure shows a high yield strength and adequate ductility at elevated temperatures. At 400 and 500 °C, the yield strength and ductility of CrMnFeCoNiAl alloy are 975.59 MPa and 6.39% and 989.48 MPa and 9.15%, respectively. An example of tailoring the strength and ductility of high-entropy alloy is demonstrated in this paper.