Effects of rare earth doping on the mechanical properties of ZrO 2 ceramics and optimization strategies

Abstract This study aims to systematically explore the regulation mechanism and optimization path of rare earth doping on the microstructure and mechanical properties of ZrO 2 ceramics. A series of rare earth oxide-doped ZrO 2 ceramics with different types and concentrations was prepared by advanced sintering technology, focusing on observing the evolution laws of key mechanical indicators such as flexural strength, fracture toughness, and hardness. The results show that the introduction of rare earth elements has a decisive impact on the phase composition and microstructure evolution of ZrO 2 ceramics through solid solution strengthening and stress field effects. Appropriate rare earth doping can effectively stabilize the high-temperature phase and trigger a significant phase transformation toughening effect, thereby greatly improving the fracture toughness of the material. It can also significantly enhance flexural strength and hardness by refining grains and strengthening grain boundaries. Microstructural analysis further reveals the segregation behavior of rare earth elements at grain boundaries and their strengthening effect on grain boundary bonding. This study clarifies the structure-property relationship between rare earth doping and the mechanical properties of ZrO 2 ceramics, providing important theoretical support and process reference for the design of high-performance ZrO 2 ceramic materials for harsh service conditions.