A sunflower-like eutectic microstructure in the AlCrFeMnNi2 high-entropy alloy with excellent compressive mechanical properties

Abstract

Although most BCC-based high-entropy alloys have high strength and excellent high temperature mechanical properties, their low plasticity greatly limit their application. It is a new challenge to develop new BCC-based high-entropy alloys with excellent combination of high strength and plasticity. In this study, we prepare a new BCC/B2 AlCrFeMnNi2 high-entropy alloy with a unique sunflower-like eutectic microstructure. This alloy has a high yield strength of 1206 MPa, a high fracture strength of 3437 MPa and large compressive plastic strain of 37.5%. The excellent compressive mechanical properties are superior to many other BCC/B2 high-entropy alloys. These properties can be attributed to its unique microstructure consisting of coherent interface between BCC and B2 phase and the bimodal distribution of the B2 precipitates. Our results can provide a meaningful reference for improving the plasticity of BCC-based high entropy alloys.