Thermally-stabilized thermal barrier coating

A gas turbine engine component comprising:

• a superalloy substrate;
• a metallic bond coat on a surface of the substrate;
• and
• a thermal barrier coating of yttria-stabilized zirconia on the bond coat, the thermal barrier coating having a microstructure with defects and pores at and between grains boundaries of the microstructure, the thermal barrier coating containing oxide impurities of at least one element chosen from the group consisting of silicon, titanium, iron, nickel, sodium, lithium, copper, manganese and potassium, the oxide impurities being present in an aggregate amount of at least 0.02 mole percent of the thermal barrier coating, the thermal barrier coating having alumina precipitates within the microstructure in an amount of at least 0.1 mole percent up to about 2 mole percent of the thermal barrier coating, at least some of the precipitates being located within the defects and pores of the microstructure, the precipitates serving to getter the oxide impurities and/or neutralize their effect so as to inhibit grain sintering and coarsening, and thereby inhibit densification of the thermal barrier coating.

A gas turbine engine component comprising:

• a superalloy substrate;
• a metallic bond coat on a surface of the substrate;
• and
• a thermal barrier coating of yttria-stabilized zirconia on the bond coat, the thermal barrier coating having a microstructure with defects and pores at and between grains boundaries of the microstructure, the thermal barrier coating containing oxide impurities of at least one element chosen from the group consisting of silicon, titanium, iron, nickel, sodium, lithium, copper, manganese and potassium, the oxide impurities being present in an aggregate amount of at least 0.02 mole percent of the thermal barrier coating, the thermal barrier coating having alumina precipitates within the microstructure in an amount of at least 0.1 mole percent up to about 2 mole percent of the thermal barrier coating to getter the oxide impurities and/or neutralize their effect so as to inhibit grain sintering and coarsening, and thereby inhibit densification of the thermal barrier coating, the precipitates having diameters in a range of about 2 to about 500 nanometers.