Patent ID: 6858334

Claim:
A zirconia-containing ceramic composition having a c/a ratio of the zirconia lattice in the range of from about 1.005 to about 1.016, and which comprises: a. a stabilizing amount up to about 10 mole % of the composition of a stabilizer component, which comprises: 1. a first metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof in an amount of from about 1.5 to about 6 mole % of the composition; 2. a second metal oxide selected from the group consisting of lanthana, neodymia and mixtures thereof in an amount of from about 0.5 to about 4 mole % of the composition; and 3. optionally ytterbia in an amount of from about 0.5 to about 4 mole % of the composition; b. hafnia in an amount of from about 0.5 to about 15 mole % of the composition; and c. optionally tantala in an amount of from about 0.5 to about 1.5 mole % of the composition.