Zirconium dioxide for aesthetic reasons, or of 2) strong, extremely durable dental prostheses constructed entirely from monolithic zirconia, with limited but constantly improving aesthetics. Zirconia stabilized with yttria (yttrium oxide), known as yttria-stabilized zirconia, can be used as a strong base material in some full ceramic crown restorations. Transformation toughened zirconia is used to make ceramic knives. Because of the hardness, ceramic-edged cutlery stays sharp longer than steel edged products. Due to its infusibility and brilliant luminosity when incandescent, it was used as an ingredient of sticks for limelight. Zirconia has been proposed to electrolyze carbon monoxide and oxygen from the atmosphere
Zirconia Toughened Alumina offers several key properties. The mechanical robustness compared to alumina is attributed to the displacive phase transformation of the metastable tetragonal ziroconia grains when the material is stressed. The stress concentration at a crack tip can cause a transformation from a tetragonal crystal structure to a monoclinic one, which has an associated volume expansion of ziroconia. This volume expansion effectively pushes back the propagation of the crack and results in higher toughness and strength. A common specimen of Zirconia Toughened Alumina will have 10-20% zirconium oxides. The 20-30% increase in strength often meets the design criteria needed at a much