Structural effects of liquid infiltration of 3Y-Zirconia with Sc, Mg and Y
The current work has investigated the effect of co-doping 3Y-Zirconia (3YSZ) with Sc, Mg and Y by wet infiltration. Pre-sintered discs of 3YSZ were immersed in diluted nitric acid solutions containing Sc, Mg or Y, and combinations of the three, trapping liquid within the porosities of the samples. Upon drying, the cations are maintained inside the pellet, making the basis for the co-doping. After sintering, mass increase confirms the co-doping effect and X-ray diffraction analysis show clear variations in atomic structure depending on the doping element. Rietveld refinements show that the wet-infiltrated samples contain the tetragonal t, t double prime and cubic c-phase in various fractions depending on the doping elements. Sc-infiltrated samples show a tendency to higher tetragonality, while the Mg-infiltrated sample obtained a single cubic phase. The multi-phase wet-infiltrated samples have a similar phase separation after sintering as 5Y-Zirconia (5YSZ), as calculated by the tetragonality deviation parameter. 3YSZ and 5YSZ sintered for 0 hours and 2 hours at 1500 degrees C show the effect of sintering time on the phase segregation. To evaluate the material properties in an application-based perspective, the Knoop hardness, translucency and grain size was measured. We conclude that liquid infiltration is a viable route to perform co-doping of Zirconia with various co-doping elements.