Low-cycle fatigue behavior and deformation mechanisms of a dual-phase Al0.5CoCrFeMnNi high-entropy alloy

•Al0.5CoCrFeMnNi demonstrates higher cyclic stress resistance than CoCrFeMnNi, meanwhile maintaining comparable cyclic strain resistance at low-to-medium strain amplitudes.•Deformation in Al0.5CoCrFeMnNi is accommodated by dislocation slip, whose mode changes from planar slip to wavy slip with increasing strain amplitude.•Upon comparison with Al0.5CoCrFeNi and CoCrNi, this work sheds light on strategies to optimize fatigue resistance of HEAs.