Phase stability, microstructural evolution and room temperature mechanical properties of TiO2 doped 8mol% Y2O3 stabilized ZrO2 (8Y-CSZ)

Abstract The effect of TiO 2 dopant on phase stability, microstructural evolution and room temperature mechanical properties of 8 mol% yttria-stabilized cubic zirconia (8Y-CSZ) was studied. The results show that TiO 2 (up to 10 wt%) can be dissolved in solid solution in the zirconia matrix. When the dopant amount is less than 5 wt%, TiO 2 doped 8Y-CSZ remains single phase cubic zirconia. Increased additions of TiO 2 destabilize the cubic phase and cause the formation of tetragonal zirconia with a resultant microstructure consisting of large cubic zirconia grains and small tetragonal zirconia grains. EDS analyses show that yttria is partitioned between these two types of grains. The solubility of TiO 2 is the highest for cubic grains which also have higher yttria concentrations. Room temperature mechanical property measurements show that hardness does not change significantly with additions of TiO 2 , but fracture toughness is more than doubled for 10 wt% TiO 2 doped 8Y-CSZ.