Thermal barrier coating system, components coated therewith and method for applying a thermal barrier coating system to components

1. A thermal barrier coating system on a base material, the system comprising:

a bond coat layer having a lower face in direct contact with the base material and an upper face;

a first ceramic layer in direct contact with the upper face of the bond coating layer, the first ceramic layer consisting of:

YTaO 4 doped zirconia, consisting of YTaO 4 and zirconia, wherein the YTaO 4 doped zirconia is zirconia doped with 15-22 mol-% YTaO 4 ; and

a second ceramic layer disposed at an outermost hot gas exposed surface of the coating system, the second ceramic layer including at least one material selected from the group consisting of:

scandia stabilized zirconia, consisting of scandia and zirconia,

ceria containing perovskite material,

Monazite material, and

spinel material.

2. The thermal barrier coating system recited in claim 1 , wherein the second ceramic layer includes one of a layer, combination, mixture, alloy, blend and multilayer structure.

3. The thermal barrier coating system recited in claim 1 , wherein the bond coat layer includes at least one of a PtAl base material and a MCrAlRX base material,

wherein M is selected from the group consisting of Fe, Co, Ni and Co/Ni,

R is selected the group consisting of Y and Yb, and

X is absent or includes at least one of Pt, Hf, Si, Zr, Ta, Re and Ru.

4. The thermal barrier coating system recited in claim 1 , wherein a lower face of the second ceramic layer directly contacts the first ceramic layer at an interface, and wherein the interface is at least one of graded and rough so as to provide mechanical adhesion between the first and second ceramic layers.

5. The thermal barrier coating system recited in claim 1 , wherein the first and second layers are single layers.

6. The thermal barrier coating system recited in claim 1 , wherein the second ceramic layer includes at least two ceramic sub-layers differing in at least one of composition, microstructure and phase composition.

7. The thermal barrier coating system recited in claim 1 , wherein the second ceramic layer has a graded porosity, including a porosity in a range of 20-80% at an interface with the first ceramic layer and a porosity in a range of 5-10% at the outermost surface.

8. The thermal barrier coating system recited in claim 1 , wherein the second ceramic layer has a thickness in a range of 300-2000 μm.

9. The thermal barrier coating system recited in claim 1 , wherein a thickness of the first ceramic layer is smaller than a thickness of the second ceramic layer.

10. The thermal barrier coating system recited in claim 1 , wherein the base material is a metal superalloy.

11. The thermal barrier coating system recited in claim 10 , wherein the superalloy is a Ni-based superalloy.

12. The thermal barrier coating system recited in claim 1 , where the first ceramic layer has a porosity in a range of 10-40%.

13. The thermal barrier coating system recited in claim 12 , wherein the first ceramic layer has a porosity in a range of 15-30%.

14. The thermal barrier coating system recited in claim 1 , wherein the first ceramic layer has a thickness in a range of 50-1000 μm.

15. The thermal barrier coating system recited in claim 14 , wherein the first ceramic layer has a thickness in a range of 100-500 μm.

16. A thermal barrier coating system on a base material, the system comprising:

a bond coat layer having a lower face in direct contact with the base material and an upper face;

a first ceramic layer in direct contact with the upper face of the bond coating layer, the first ceramic layer consisting of:

YTaO 4 doped zirconia, consisting of YTaO 4 and zirconia, wherein the YTaO 4 doped zirconia is zirconia doped with 14-17 mol-% YTaO 4 ;

a second ceramic layer disposed at an outermost hot gas exposed surface of the coating system, the second ceramic layer including at least one material selected from the group consisting of:

scandia stabilized zirconia, consisting of scandia and zirconia,

ceria containing perovskite material,

Monazite material, and

spinel material.

17. The thermal barrier coating system recited in claim 16 , the ceria containing perovskite material is selected from at least one of BaCeO 3 and SrCeO 3 , the Monazite includes LaPO 4 , and/or the spinel includes at least one of BaY 2 O 4 and SrY 2 O 4 .

18. A thermal barrier coating system on a base material, the system comprising:

a bond coat layer having a lower face in direct contact with the base material and an upper face;

a first ceramic layer in direct contact with the upper face of the bond coating layer, the first ceramic layer consisting of YTaO 4 doped zirconia, wherein the YTaO 4 doped zirconia is zirconia doped with 15-22 mol-% YTaO 4 ; and

a second ceramic layer disposed at an outermost hot gas exposed surface of the coating system, the second ceramic layer including at least one material selected from the group consisting of:

scandia stabilized zirconia,

ceria containing perovskite material,

yttrium aluminium garnet material,

Monazite material, and

spinel material.

19. A thermal barrier coating system on a base material, the system comprising:

a bond coat layer having a lower face in direct contact with the base material and an upper face;

a first ceramic layer in direct contact with the upper face of the bond coating layer, the first ceramic layer consisting of YTaO 4 doped zirconia, wherein the YTaO 4 doped zirconia is zirconia doped with 14-17 mol-% of YTaO 4 ; and

a second ceramic layer disposed at an outermost hot gas exposed surface of the coating system, the second ceramic layer including at least one material selected from the group consisting of:

scandia stabilized zirconia,

ceria containing perovskite material,

yttrium aluminium garnet material,

Monazite material, and

spinel material.