The effect of titania doping on structure and mechanical properties of calcia-stabilized zirconia ceramic

Abstract

The effect of titania doping on density, phase composition, and mechanical properties of calcia-stabilized tetragonal zirconia ceramics (Ca-TZP) was investigated. The samples were prepared via milling, spray drying and consequent uniaxial pressing of the powders of the chosen composition. The concentrations of titania of up 1 mol% were investigated. Addition of titania moderately improved relative density of the sintered ceramics from 98.2% in titania-free material to 99.3% in 0.5 mol% titania ceramic. Introduction of titania resulted in increase of transformability of tetragonal zirconia phase deduced from the change of lattice parameters and content of monoclinic zirconia phase on fracture surfaces. It was revealed that hardness of titania-doped Ca-TZP decreased from 12.2 GPa in undoped ceramic to 11.3 GPa in material with 0.75 mol% titania. Fracture toughness, on the contrary, demonstrated a clear extremum of 9.1 MPa·m0.5 in 0.5–0.65 mol% titania range as compared to ∼5 MPa·m 0.5 in undoped Ca-TZP. Keywords: Zirconia, TZP, Titania, Dopant, Mechanical properties