Mechanical Properties and Microstructure of the Shear Band Formed at Cryogenic Temperature in the NiCrFe Medium-Entropy Alloy

There are nanotwins in the shear band formed in a moment (about 10−5 s) in some NiCrFe-based medium-entropy alloys (MEAs), and these shear bands can be recognized as a special kind of materials due to their high strength and good plasticity. In this study, the single shear band of the NiCrFe MEA was prepared at 77 K. A series of characterizations were carried out to analyze the microstructures in the shear band. The strength of the shear band was investigated by the split Hopkinson pressure bar and in-situ compression. The micropillar in the shear band containing nanotwins exhibits excellent strength-plasticity synergy. The compressive yield strength of the shear band measured by in-situ compression is 175