Effects of Cryogenic Temperature on Adiabatic Shear Localization in Equiatomic NiCrFe Medium-Entropy Alloy

Nanotwinning is an effective way to achieve the trade-off between strength and plasticity in metallic materials. The shear band is a typical form of deformation carrier at high strain rate, and there are nanotwins in the shear band in some medium-entropy alloys (MEAs). In this work, the adiabatic shear localization at 298 and 77 K in the equiatomic NiCrFe MEA is investigated, and a series of characterization methods are carried out to study the shear band and internal microstructures. The shear band of the NiCrFe MEA exhibits higher strength of 2072 MPa and good plasticity with a true strain reaching 1.63 at 77 K. The average width of the shear band reduces by 40