Thermal expansion of zirconia–zirconium titanate materials obtained by slip casting of mixtures of Y-TZP–TiO2

The objective of this work was to establish the optimum conditions to get zirconia materials with different proportions of zirconium titanate by reaction sintering of ZrO2 stabilized with 3 mol% of Y2O3 (Y-TZP) and TiO2. The green bodies were fabricated from stable colloidal suspensions of the powders by slip casting in plaster moulds.The rheological characterization of the suspensions allowed the establishment of the optimum green processing conditions. Reaction sintering was performed at 1500 °C during 2 h, and the obtained materials have been characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy with energy dispersive X-ray microanalysis (FE-SEM-EDX). Under these conditions, zirconium titanate materials with tetragonal zirconia could not be obtained because a solid solution of cubic zirconia with titania and yttria is formed at 1500 °C. The thermal expansion of the materials was determined by differential dilatometry from room temperature up to 850 °C, demonstrating that the incorporation of zirconium titanate reduces the thermal expansion of zirconia.