An inverse Hall-Petch behavior and improving toughness in translucent nanocrystalline high-entropy zirconate ceramic

Short-range order is a new strengthening effect that can significantly affect the mechanical properties of high-entropy materials. Furthermore, simulation results show that this strengthening effect at a quasi-atomic scale can suppress the grain size softening, leading to the disappearance of inverse Hall-Petch behavior in nanocrystalline high-entropy materials. In this work, the evident inverse Hall-Petch behavior is confirmed in the translucent nanocrystalline high-entropy ceramic (HEC) with an average grain size below 10 nm, fabricated by a high-pressure low-temperature sintering technique. Besides, the as-obtained nanocrystalline HEC also shows an improving fracture toughness compared with the corresponding coarse-crystalline HEC.