A multi-phase CrMnFeCoNiAl0.75 high-entropy alloy with high strength at intermediate temperature

Abstract

High-entropy alloys with a superalloy-like microstructure show excellent mechanical properties at elevated temperatures. In this paper, a multi-phase high-entropy alloy CrMnFeCoNiAl0.75 was developed. Based on the microstructure characterization by XRD, SEM, TEM and 3D-APT, it was found that the alloy was composed of FCC phase, BCC phase, and B2 phase. The mechanical properties evaluation showed that the alloy had high compression yield strength of 1194 MPa at room temperature and could preserve high yield strength of 1070 MPa at 500 °C. Further increase in the temperature beyond 600 °C resulted in alloy softening. The alloy showed limited strain of 2.72% at room temperature, but it exhibited adequate deformability at elevated temperatures up to 500 °C (strain >20%). The strengthening mechanisms of the alloy at different temperatures were discussed.