UNDERSTANDING DIAMOND NANOPARTICLE EVOLUTION DURING ZIRCONIA SPARK PLASMA SINTERING

摘要

In this study, pure ZrO_2 and ZrO_2-diamond composite are spark plasma sintered in order to understand the evolution of diamond nanoparticles during spark plasma sintering and on the material properties. During spark plasma sintering, diamond is effectively retained, which is impossible for conventional sintering. However, it contributes adversely to the grain size distribution, densification, and hardness/reduced modulus improvement. Thermal treatment at 1250°C removes the diamond phase and refines the ZrO_2 microstructure; however, the compromise on the mechanical properties persists because of the pores formed after the diamond phase removal. Future work should focus on refining the spark plasma sintering process so that the function of the diamond phase in the ZrO_2 matrix can be effectively utilized.