Zirconium dioxide coating on particles of titanium dioxide pigments, as a refractory material, in insulation, abrasives and enamels. Stabilized zirconia is used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. This high ionic conductivity (and a low electronic conductivity) makes it one of the most useful electroceramics. Zirconium dioxide is also used as the solid electrolyte in electrochromic devices. Zirconia is a precursor to the electroceramic lead zirconate titanate ("PZT"), which is a high-K dielectric, which is found in myriad components. The very low
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