Study on the Strengthening Mechanism of AlCoCrFeNi2.1 Eutectic High-Entropy Alloy

Eutectic high-entropy alloys (EHEAs) possess unique microstructures and excellent properties. In this study, it was found that the microstructure of as-cast AlFeCoCrNi2.1 can be classified into lamellar regular structure, irregular structure, and grain boundaries. The solidification process of AlFeCoCrNi2.1 was theoretically speculated. Compression tests revealed that the yield strength of AlFeCoCrNi2.1 reached 724.39 MPa, the ultimate fracture toughness reached 3556.4 MPa, and the as-cast average hardness reached 349.9 HV0.3. Furthermore, this study investigated the microstructural strengthening mechanisms of AlFeCoCrNi2.1 EHEA. The results indicated that different compression stages had varying effects on orientation distribution and dislocation slip during the compression process. Furthermore, it was found that the irregular structure and grain boundaries played a major role in the alloy strengthening.