Orientation dependence of the mechanical behaviour of (CoCrFeNi)94Ti2Al4 high-entropy alloy single crystals with γ′-phase particles

Abstract The kinetics of precipitation hardening at 1073 K of the (CoCrFeNi)94Ti2Al4 high-entropy alloy (HEA) was investigated during tension along [0 0 1] and [ 1 ¯ 44 ] orientations. It was shown that at a high level of deforming stresses, the critical resolved shear stresses (CRSS) τcr began to depend on the crystal orientation: τcr [ 1 ¯ 44 ] [ 1 ¯ 44 ] -oriented crystals was developed after strain of 5%, and the fracture contained elements of brittle and ductile fracture. In [0 0 1]-oriented crystals, deformation occurred by slip, and fracture was ductile.