Ceria-zirconia oxides is thermodynamically favorable in a wide range of solid solution compositions, which means that ceria-zirconia is metastable with respect to phase separation. Ceria-zirconia is widely used as a component in current three-way catalytic converters. The ceria-based component of the converter has several functions, including promoting the dispersion of the noble metals in the catalyst, but also storing and releasing oxygen. The incorporation of zirconium in modern converters, forming ceria-zirconia, improves the performance of the catalyst by enhancing the resistance of the material to sintering, and simultaneously increasing the ability of the oxide to accommodate oxygen vacancies in its structure.
Zirconia Toughened Alumina lower cost. Depending on the percentage that is Zirconium, the properties of this ceramic can be manipulated for the applications required. Zirconia Toughened Alumina is generally referred as the intermediary between Alumina and Zirconium and as priced as such. This gives the ZTA a much lower price range than other similar materials. The increase in composite strength is done by a process called Stress Induced Transformation Toughening. This process causes internal strains, which causes crack in the structure of the Zirconium. Because of the crack, the Zirconium particles allowed to switch phases and move more freely amongst the Alumina particles.