Claims

1. A process of coating an article, comprising:(1) applying a ceramic compound;(2) applying at least one inert compound, wherein said at least one inert compound comprises an inert compound comprising a hexagonal crystalline structure of formula (II):A_{4B.sub.6X.sub.6O.sub.26} (II)where A comprises at least one of the metals selected from the group consisting of is Ca⁺², Mg⁺², Fe⁺², Na⁺, K⁺, Gd⁺³, Zr⁺⁴, Hf⁺⁴, Y⁺², Sc⁺², Sc⁺³, In⁺³, La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V⁺², Ta⁺², Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², Cd⁺², and;where B comprises at least one of the metals selected from the group consisting of Gd⁺³, Y⁺², Sc⁺², In⁺³, Zr⁺⁴, Hf⁺⁴, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen; and(3) heat treating said article.

2. The process of claim 1, wherein the at least one inert compound further comprises an inert compound comprising a cubic crystalline structure of formula (I):A_{3B.sub.2X.sub.3O.sub.12} (I)where A comprises at least one of the metals selected from the group consisting of Ca⁺², Gd⁺³, In⁺³, Mg⁺², Na⁺, K⁺, Fe⁺², La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V⁺², Ta⁺², Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², and Cd⁺²;where B comprises at least one of the metals selected from the group consisting of Zr⁺⁴, Hf⁺⁴, Gd⁺³, Al⁺³, Fe⁺³, La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², In⁺³, Sc⁺², Y⁺², Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Fe⁺³, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen.

3. The process of claim 1, wherein:the applying said ceramic compound comprises applying to at least one surface of an article to form a layer of ceramic compound; andthe applying said at least one inert compound comprises applying upon said ceramic compound layer to form a protective layer.

4. The process of claim 1, wherein:the applying said ceramic and the applying said at least one inert compound comprises grading the ceramic compound and at least one inert compound upon at least one surface of an article to form a graded thermal barrier coating.

5. The process of claim 4, wherein grading comprises forming said graded thermal barrier coating having at least a surface where said at least one inert compound is present in an amount of about 100 percent by weight of said graded thermal barrier coating.

6. The process of claim 1, further comprising (4) drying said article prior to said heat treating (3).

7. The process of claim 6, further comprising (5) repeating steps (2) and (4) prior to said heat treating (3).

8. The process of claim 1, wherein applying said ceramic compound comprises applying said ceramic compound using a process selected from the group consisting of physical vapor deposition, thermal spraying, sputtering, sol gel and slurry.

9. The process of claim 8, wherein said physical vapor deposition process is an electron beam physical vapor deposition process.

10. The process of claim 8, wherein said thermal spraying process is a high velocity oxygen fuel thermal spraying process or an air plasma thermal spraying process.

11. The process of claim 1, wherein heat treating comprises heating said coated article at about 1200° F. to about 2000° F. for about 30 minutes to about 360 minutes.

12. The process of claim 1, wherein said applying said at least one inert compound comprises using a process selected from the group consisting of physical vapor deposition, thermal spraying, sputtering, sol gel, slurry, dipping, brushing, and painting.

13. The process of claim 12, wherein said physical vapor deposition process is an electron beam physical vapor deposition process.

14. The process of claim 12, wherein said thermal spraying process is an air plasma spraying process.

15. The process of claim 12, wherein said thermal spraying process is a high velocity oxygen fuel thermal spraying process.

16. The process of claim 1, wherein the process for applying said ceramic compound to said article is different than the process for applying said inert compound to said ceramic compound layer.

17. The process of claim 1, wherein the process for applying said ceramic compound to said article is the same as the process for applying said inert compound to said ceramic compound layer.

18. The process of claim 1, further comprising the step of applying a layer of bond coat material on at least one surface of said article prior to applying said layer of ceramic compound.

19. The process of claim 18, wherein applying said bond coat layer comprises a process selected from the group consisting of diffusion processes, low pressure plasma-spray, air plasma-spray, sputtering, cathodic arc, electron beam physical vapor deposition, high velocity plasma spray processes, combustion processes, wire spray processes, laser beam cladding, and electron beam cladding.

20. The process of claim 1, wherein applying said at least one inert compound comprises the steps of:contacting said article with a suspension of said inert compound, and at least one of each of a dispersant, an ultra-violet curable resin and optionally a surfactant at a temperature of about 68° F. to about 150° F. at a pressure of about 10 torr to about 100 torr for about 2 minutes to about 5 minutes;curing said article using ultra-violet light energy for about 10 seconds to about 60 seconds; andheat treating said article at a temperature of about 750° F. to about 1600° F. for about 10 minutes to about 90 minutes.

21. The process of claim 1, wherein applying said at least one inert compound comprises the steps of:contacting said article with a suspension of said inert compound, and at least one of each of a dispersant, a heat curable resin and optionally a surfactant at a temperature of about 68° F. to about 150° F. at a pressure of about 10 torr to about 100 torr for about 2 minutes to about 10 minutes;curing said article at a temperature of about 300° F. for about 20 minutes to about 60 minutes; andheat treating said article at a temperature of about 750° F. to about 1600° F. for about 10 to about 90 minutes.

22. A thermal barrier coating comprising:a ceramic compound and at least one inert compound, wherein said at least one inert compound comprises a first inert compound comprising a hexagonal crystalline structure of formula (II):A_{4B.sub.6X.sub.6O.sub.26} (II)where A comprises at least one of the metals selected from the group consisting of Ca⁺², Mg⁺², Na⁺, K⁺, Fe⁺², La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V^+2Ta.sup.+2, Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², and Cd⁺²;where B comprises at least one of the metals selected from the group consisting of Gd⁺³, Y⁺², Sc⁺², In⁺³, Sc⁺², Y⁺², Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen.

23. The thermal barrier coating of claim 22, wherein said at least one inert compound comprises a second inert compound comprising a cubic crystalline structure of formula (I):A_{3B.sub.2X.sub.3O.sub.12} (I)where A comprises at least one of the metals selected from the group consisting of Ca⁺², Gd⁺³, In⁺³, Mg⁺², Na⁺, K⁺, Fe⁺², La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V⁺², Ta⁺², Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², and Cd⁺²;where B comprises at least one of the metals selected from the group consisting of Zr⁺⁴, Hf⁺⁴, Gd⁺³, Al⁺³, Fe⁺³, La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², In⁺³, Sc⁺², Y⁺², Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Fe⁺³, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen,

24. The thermal barrier coating of claim 23, wherein said ceramic compound comprises a stabilized zirconate or a stabilized hafnate.

25. The thermal barrier coating of claim 23, wherein said ceramic compound is selected from the group consisting of yttria stabilized zirconia, calcia stabilized zirconia, magnesia stabilized zirconia, yttria stabilized hafnia, calcia stabilized hafnia and magnesia stabilized hafnia.

26. The thermal barrier coating of claim 23, wherein said second inert compound is garnet.

27. The thermal barrier coating of claim 23, wherein said first inert compound is oxyapatite.

28. The thermal barrier coating of claim 23, wherein said at least one inert compound comprises a porosity of no more than about 30% by volume of said at least one inert compound.

29. The thermal barrier coating of claim 23, wherein said at least one inert compound comprises a porosity of no more than about 20% by volume of said at least one inert compound.

30. A coated article comprising:an article comprising at least one surface; anda thermal barrier coating according to claim 22 disposed thereupon.

31. The coated article of claim 30, wherein said first inert compound comprises a first layer disposed upon a second layer comprising said ceramic compound.

32. The coated article of claim 30, wherein said first inert compound and said ceramic compound comprise a graded layer.

33. The coated article of claim 32, wherein at least at a surface said at least one inert compound is present in an amount of about 100 percent by weight.

34. The coated article of claim 30, wherein said article is selected from the group consisting of blades, vanes, stators, and mid-turbine frames, seals, combustor panels, combustor chambers, combustor bulkhead shields, disk side plates and fuel nozzle guides.

35. The coated article of claim 34, wherein said at least one inert compound comprises a layer having a thickness of about 5 mils to about 15 mils.

36. The coated article of claim 30, further comprising a bond coat material on at least one surface of said article prior to applying said layer of ceramic based compound.

37. A coating, comprising:a reaction product of at least one silica based material and a thermal barrier coating composition comprising:a ceramic compound; andat least one inert compound,wherein said at least one inert compound comprises a first inert compound comprising hexagonal crystalline structure of formula (II):A_{4B.sub.6X.sub.6O.sub.26} (II)where A comprises at least one of the metals selected from the group consisting of is Ca⁺², Mg⁺², Fe⁺², Na⁺, K⁺, Gd⁺³, Zr⁺⁴, Hf⁺⁴, Y⁺², Sc⁺², Sc⁺³, In⁺³, La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V⁺², Ta⁺², Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², and Cd⁺²;where B comprises at least one of the metals selected from the group consisting of Gd⁺³, Y⁺², Sc⁺², In⁺³, Zr⁺⁴, Hf⁺⁴, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen.

38. The coating of claim 37 wherein said at least one inert compound further comprises a second inert compound comprising a cubic crystalline structure of formula (I):A_{3B.sub.2X.sub.3O.sub.12} (I)where A comprises at least one of the metals selected from the group consisting of Ca⁺², Gd⁺³, In⁺³, Mg⁺², Na⁺, K⁺, Fe⁺², La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², Sc⁺², Y⁺², Ti⁺², Zr⁺², Hf⁺², V⁺², Ta⁺², Cr⁺², W⁺², Mn⁺², Tc⁺², Re⁺², Fe⁺², Os⁺², Co⁺², Ir⁺², Ni⁺², Zn⁺², and Cd⁺²;where B comprises at least one of the metals selected from the group consisting of Zr⁺⁴, Hf⁺⁴, Gd⁺³, Al⁺³, Fe⁺³, La⁺², Ce⁺², Pr⁺², Nd⁺², Pm⁺², Sm⁺², Eu⁺², Gd⁺², Tb⁺², Dy⁺², Ho⁺², Er⁺², Tm⁺², Yb⁺², Lu⁺², In⁺³, Sc⁺², Y⁺², Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³;where X comprises at least one of the metals selected from the group consisting of Si⁺⁴, Ti⁺⁴, Al⁺⁴, Fe⁺³, Cr⁺³, Sc⁺³, Y⁺³, V⁺³, Nb⁺³, Cr⁺³, Mo⁺³, W⁺³, Mn⁺³, Fe⁺³, Ru⁺³, Co⁺³, Rh⁺³, Ir⁺³, Ni⁺³, and Au⁺³; andwhere O is oxygen.