Extreme thermal stability in crystal-amorphous nanocrystalline CoCrFeMnNi high entropy alloy

Abstract

This work investigates the crystal-amorphous CoCrFeMnNi dual-phase nanocrystalline high entropy alloy (HEA), focusing on how the amorphous layer affects the abnormal crystal growth. The result showed that the wide amorphous layer and high entropy effects in grain boundary, which provide lower driving force for grain growth, the average grain size of the crystal-amorphous HEA only increases to 8 nm after annealing at 500 ℃ for 1 h, indicating the exceptional thermal stability. Therefore, the crystal-amorphous dual-phase HEA offers a new model for developing advanced nanocrystalline materials with outstanding thermal stability.