Twin-coupled shear bands in an ultrafine-grained CoCrFeMnNi high-entropy alloy deformed at 77K

Two different types of shear bands generate in ultrafine-grained (UFG) CoCrFeMnNi high-entropy alloys deformed at 77 K, i.e. commonly-observed low angle grain boundary (LAGB) type and unusual twin-coupled type. Twin-coupled exhibit a misorientation 56–67° with the matrix, contrast to LAGB band 6–12°. Both annealing twins deformation can act as precursor for bands, where dislocation accumulation along twin boundaries tune orientation lamella. These observations suggest that an important plastic carrier materials under extreme conditions.