Unveiling anneal hardening in dilute Al-doped AlxCoCrFeMnNi (x = 0, 0.1) high-entropy alloys

•Anneal hardening phenomenon has been observed in dilute Al-doped alxcocrfemnni (x = 0, 0.1) high-entropy alloys, where peak hardness is reached at an annealing temperature of 500 °C (recrystallization temperature).•Dislocation substructure strengthening is identified to explain the observed annealing hardening phenomenon.•The dilute addition of al reduces the hardness/strength of the base alloy, this al induced softening could be associated with the presence of short-range cluster.