Microstructure and mechanical properties of dense ZTA ceramics with high Cr2O3 solution

Zirconia toughened alumina (ZTA) ceramics are commonly used in various industries. Adding suitable additives is an effective way to improve the performance of ZTA ceramics. However, the common reinforcement in ZTA, chromia (Cr 2 O 3 ), tends to volatilize at high temperature in the presence of oxygen, limiting ceramic densification. Consequently, additional amounts of Cr 2 O 3 are typically limited to below 1 wt%. In this study, spark plasma sintering was utilized to inhibit the volatilization of Cr 2 O 3 . Dense ZTA ceramics with high Cr 2 O 3 content (from 1 to 10 wt%) were prepared at 1350 °C. The impact of the solid solution on the structure and properties of the ceramics was investigated. The findings demonstrate that the high Cr 2 O 3 solution can regulate the grain size in the matrix, leading to an enhancement in both hardness and fracture toughness. The optimum performance of the sample was obtained with a 5 wt% dosage of Cr 2 O 3 , where the maximum values of Vickers hardness and fracture toughness were 20.66 GPa and 6.37 MPa m 1/2 , respectively.