CMAS resistant thermal barrier coating

Abstract

A turbine engine component is provided which has a substrate and a thermal barrier coating applied over the substrate. The thermal barrier coating comprises alternating layers of yttria-stabilized zirconia and a molten silicate resistant material. The molten silicate resistant outer layer may be formed from at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium or may be formed from a gadolinia-stabilized zirconia. If desired, a metallic bond coat may be present between the substrate and the thermal barrier coating system. A method for forming the thermal barrier coating system of the present invention is described.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a turbine engine component with the coating of the present invention; and

FIG. 2 is a schematic representation of a turbine engine component with an alternative coating system in accordance with the present invention.

Claims

1. A turbine engine component comprising: a substrate; anda thermal barrier coating system comprising alternating layers of a yttria-stabilized zirconia material and a molten silicate resistant material applied over said substrate.

2. The turbine engine component according to claim 1, wherein said molten silicate resistant material comprises at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium.

3. The turbine engine component according to claim 1, wherein the molten silicate resistant material comprises a gadolinia stabilized zirconia.

4. The turbine engine component according to claim 3, wherein said gadolinia stabilized zirconia consists of from 25 to 99.9 wt % gadolinia and the balance zirconia.

5. The turbine engine component according to claim 1, wherein each said layer of a molten silicate resistant material has a thickness in the range of from 0.5 to 50 mils.

6. The turbine engine component according to claim 1, wherein each said layer of a molten silicate resistant material has a thickness in the range of from 1.0 to 5.0 mils.

7. The turbine engine component according to claim 1, wherein at least one layer of said yttria-stabilized zirconia coating contains from 4.0 to 25 wt % yttria.

8. The turbine engine component according to claim 1, wherein at least one layer of said yttria-stabilized zirconia contains from 6.0 to 9.0 wt % yttria.

9. The turbine engine component according to claim 1, wherein at least one layer of said yttria-stabilized zirconia consists of from 4.0 to 25 wt % yttria and the balance zirconia.

10. The turbine engine component according to claim 1, wherein at least one layer of said yttria-stabilized zirconia coating consists of from 6.0 to 9.0 wt % yttria and the balance zirconia.

11. The turbine engine component according to claim 1, wherein each said yttria-stabilized zirconia layer has a thickness in the range of from 1.0 to 50 mils.

12. The turbine engine component according to claim 1, wherein each said yttria-stabilized zirconia coating has a thickness in the range of from 1.0 to 5.0 mils.

13. The turbine engine component according to claim 1, wherein said substrate is formed from a material selected from the group consisting of a nickel based alloy, a cobalt based alloy, and a molybdenum based alloy.

14. The turbine engine component according to claim 1, further comprising a metallic bond coat between said substrate and said thermal barrier coating.

15. A thermal barrier coating system comprising: a first layer of yttria-stabilized zirconia;a first layer of a molten silicate resistant material deposited over said first layer of yttria-stabilized zirconia;a second layer of yttria-stabilized zirconia deposited over said first layer of said molten silicate resistant material; anda second layer of molten silicate resistant material deposited over said second layer of said yttria-stabilized material.

16. The thermal barrier coating system of claim 15, further comprising at least one additional layer of yttria-stabilized zirconia and at least one additional layer of said molten silicate resistant material.

17. The thermal barrier coating system of claim 15, wherein said molten silicate resistant material consists of at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium.

18. The thermal barrier coating system according to claim 15, wherein the molten silicate resistant material consists of a gadolinia stabilized zirconia.

19. The thermal barrier coating system according to claim 18, wherein said gadolinia stabilized zirconia consists of from 25 to 99.9 wt % gadolinia and the balance zirconia.

20. The thermal barrier coating system according to claim 18, wherein said gadolinia stabilized zirconia consists of from 40 to 70 wt % gadolinia and the balance zirconia.

21. The thermal barrier coating system according to claim 15, wherein each said layer of molten silicate resistant material has a thickness in the range of from 0.5 to 50 mils.

22. The thermal barrier coating system according to claim 15, wherein each said layer of molten silicate resistant material has a thickness in the range of from 1.0 to 5.0 mils.

23. The thermal barrier coating system according to claim 15, wherein at least one layer of said yttria-stabilized zirconia contains from 4.0 to 25 wt % yttria.

24. The thermal barrier coating system according to claim 15, wherein at least one layer of said yttria-stabilized zirconia contains from 6.0 to 9.0 wt % yttria.

25. The thermal barrier coating system according to claim 15, wherein at least one layer of said yttria-stabilized zirconia consists of from 4.0 to 25 wt % yttria and the balance zirconia.

26. The thermal barrier coating system according to claim 15, wherein at least one layer of said yttria-stabilized zirconia consists of from 6.0 to 9.0 wt % yttria and the balance zirconia.

27. The thermal barrier coating system according to claim 15, wherein each said layer of yttria-stabilized zirconia has a thickness in the range of from 0.5 to 50 mils.

28. The thermal barrier coating system according to claim 15, wherein each said layer of yttria-stabilized zirconia has a thickness in the range of from 1.0 to 5.0 mils.

29. A method for providing a component with protection against sand related distress comprising the steps of: providing a substrate;forming a thermal barrier coating system by depositing alternating layers of a yttria-stabilized zirconia material and a molten silicate resistant material on the substrate.

30. The method according to claim 29, wherein said step of depositing alternating layers comprises depositing a layer of a molten silicate resistant material consisting of at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium.

31. The method according to claim 29, wherein said step of depositing alternating layers comprises depositing at least one layer of gadolinia stabilized zirconia.

32. The method according to claim 31, wherein said gadolinia stabilized zirconia depositing step comprises depositing a material consisting of from 25 to 99.9 wt % gadolinia and the balance zirconia.

33. The method according to claim 31, wherein said gadolinia stabilized zirconia depositing step comprises depositing a material consisting of from 40 to 70 wt % gadolinia and the balance zirconia.

34. The method according to claim 29, wherein said molten silicate resistant material depositing step comprises depositing a layer having a thickness in the range of from 0.5 to 50 mils over each respective layer of the yttria-stabilized zirconia material.

35. The method according to claim 29, wherein said molten silicate resistant material depositing step comprises depositing a layer having a thickness in the range of from 1.0 to 5.0 mils over each respective layer of the yttria-stabilized zirconia material.

36. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises depositing a material containing from 4.0 to 25 wt % yttria.

37. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises depositing a material containing from 6.0 to 9.0 wt % yttria.

38. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises depositing a material consisting of from 4.0 to 25 wt % yttria and the balance zirconia.

39. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises depositing a material containing from 6.0 to 9.0 wt % yttria and the balance zirconia.

40. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises forming each said layer with a thickness in the range of from 0.5 to 50 mils.

41. The method according to claim 29, wherein said yttria-stabilized zirconia layer depositing step comprises forming a layer having a thickness in the range of from 1.0 to 5.0 mils.

42. The method according to claim 29, wherein said substrate providing step comprises providing a substrate formed from a material selected from the group consisting of a nickel based alloy, a cobalt based alloy, and a molybdenum based alloy.

43. The method according to claim 29, further comprising: placing said substrate into a coating chamber;heating said substrate in said coating chamber to a temperature in the range of from 1700 to 2000° F.;maintaining pressure in said coating chamber at a pressure in the range of from 0.1 to 1.0 millitorr; andsequentially forming said yttria-stabilized zirconia layers and said molten silicate resistant material layers.

44. The method according to claim 29, further comprising depositing a metallic bond coat layer between said substrate and said thermal barrier coating system.

45. A coating system for a component comprising alternating layers of a yttria-stabilized zirconia material and a molten silicate resistant material, and each said layer of said molten silicate resistant material having a barrier phase of at least one of oxyapatite and garnet to resist penetration of molten silicate material.

47. The coating system of claim 45, wherein said molten silicate resistant material consists of at least one oxide of a material selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, indium, zirconium, hafnium, and titanium.

48. The coating system of claim 45, wherein said molten resistant material consists of gadolinia-stabilized zirconia.