Solidification Microstructure and Mechanical Properties of Bulk Near-Eutectic AICoCrFeNi_(2.2) High Entropy Alloy

摘要

A 4Kg grade AlCoCrFeNi_(2.2) high entropy alloy was prepared by low vacuum medium frequency induction melting. The microstructure results showed that the microstructure and composition of the ingot were uniform. The microstructures were composed of primary Ni-rich FCC phase and eutectic structure. The eutectic structure was composed of Ni-rich FCC phase and Al-rich B2 phase. The hardness results showed no significant difference in Vickers hardness between different parts of the ingot, and fluctuated within the range of HV260 ± 20. The compression test results showed that there was no significant difference in compression performance between different parts of the ingot. The AlCoCrFeNi_(2.2) high entropy alloy had excellent compression performance, the yield strength reached 600 MPa, the fracture strength reached 2200 MPa, and the compression ratio was greater than 40%. Above all, the near-eutectic AlCoCrFeNi_(2.2) high-entropy alloy had the characteristics of good casting ability, high strength, good plasticity, and was easy to realize the preparation of large-volume non-segregation ingot.