Calcium-magnesium-aluminosilicate resistant coating and process of forming a calcium-magnesium-aluminosilicate resistant coating

Patent metadata

Field	Value
Publication number	US-9995169-B2
Application number	US-201313801547-A
Country	US
Kind code	B2
Filing date	Mar 13, 2013
Priority date	Mar 13, 2013
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A process of forming a calcium-magnesium-aluminosilicate (CMAS) penetration resistant coating, and a CMAS penetration resistant coating are disclosed. The process includes providing a thermal barrier coating having a dopant, and exposing the thermal barrier coating to calcium-magnesium-aluminosilicate and gas turbine operating conditions. The exposing forming a calcium-magnesium-aluminosilicate penetration resistant layer. The coating includes a thermal barrier coating composition comprising a dopant selected from the group consisting of rare earth elements, non-rare earth element solutes, and combinations thereof. Additional or alternatively, the coating includes a thermal barrier coating and an impermeable barrier layer or a washable sacrificial layer positioned on an outer surface of the thermal barrier coating.

First claim

What is claimed is:

1. A process of forming a calcium-magnesium-aluminosilicate penetration resistant layer, the process comprising:
providing a thermal barrier coating on a substrate to form a coating-substrate system, the thermal barrier coating comprising at least one layer of a thermal barrier coating composition; and
exposing the thermal barrier coating to calcium-magnesium-aluminosilicate and gas turbine operating conditions;
wherein the exposing forms the calcium-magnesium-aluminosilicate penetration resistant layer;
wherein the thermal barrier coating composition includes a thermal conductivity which is at least about 30% less than the thermal conductivity of 7YSZ; and
wherein:
all of the thermal barrier coating composition in the coating-substrate system includes, by weight, between about 50% and about 85% of the dopant incorporated in the thermal barrier composition;
all of the thermal barrier coating composition in the coating-substrate system includes, by weight, between about 30% and about 85% of a dopant incorporated in the thermal barrier composition, with the dopant being selected from the group consisting of Yb, La, Sm, Ti, Al, InFeZnO 4 , Yb 2 O 3 , La 2 O 3 , Sm 2 O 3 , TiO 2 , Al 2 O 3 , mischmetal oxides, and combinations thereof; or
all of the thermal barrier coating composition in the coating-substrate system includes, by weight, between about 50% and about 85% of the dopant incorporated in the thermal barrier composition, with the dopant being selected from the group consisting of Yb, La, Sm, Ti, Al, InFeZnO 4 , Yb 2 O 3 , La 2 O 3 , Sm 2 O 3 , TiO 2 , Al 2 O 3 , mischmetal oxides, and combinations thereof.

2. The process of claim 1 , further comprising forming a dense sealant reaction layer with the calcium-magnesium-aluminosilicate penetration resistant layer.

3. The process of claim 1 , further comprising forming an outer face of the thermal barrier coating with the calcium-magnesium-aluminosilicate penetration resistant layer.

4. The process of claim 1 , wherein the dopant is selected from the group consisting of Yb, La, Sm, Ti, Al, InFeZnO 4 , Yb 2 O 3 , La 2 O 3 , Sm 2 O 3 , TiO 2 , Al 2 O 3 , mischmetal oxides, and combinations thereof.

5. The process of claim 1 , wherein all of the thermal barrier coating composition in the coating-substrate system includes, by weight, between about 50% and about 85% of the dopant incorporated in the thermal barrier composition.

6. The process of claim 1 , wherein the calcium-magnesium-aluminosilicate penetration resistant layer includes crystallized apatite.

7. The process of claim 1 , further comprising an impermeable barrier layer with the calcium-magnesium-aluminosilicate penetration resistant layer.

8. The process of claim 7 , wherein the impermeable barrier layer comprises oxides selected from the group consisting of SiOxNy, Ta 2 O 5 , HfO 2 , TiO 2 , and combinations thereof.

9. The process of claim 7 , wherein the impermeable barrier layer comprises non-oxides selected from the group consisting of carbides, nitrides, silicides, and combinations thereof.

10. The process of claim 1 , further comprising forming a washable sacrificial layer with the calcium-magnesium-aluminosilicate penetration resistant layer.

11. The process of claim 10 , wherein the washable sacrificial layer includes magnesia, chromia, calcia, or a combination thereof.

12. The process of claim 10 , further comprising forming ash deposits from the washable sacrificial layer.

13. The process of claim 12 , further comprising removing the ash deposits with a water washing step.

14. The process of claim 10 , further comprising forming diopsides from MgO in the washable sacrificial layer.

15. The process of claim 14 , wherein the diopside facilitates crystallization of a calcium-magnesium-aluminosilicate melt.

16. The process of claim 1 , wherein the at least one layer of thermal barrier coating composition includes a plurality of layers.

17. The process of claim 16 , wherein each of the plurality of layers comprises a different dopant.

18. The process of claim 1 , wherein the gas turbine operating conditions include temperatures of at about 1600° C. for about 24,000 hours.

19. A process of forming a calcium-magnesium-aluminosilicate penetration resistant layer, the process comprising:
providing a thermal barrier coating on a substrate to form a coating-substrate system, the thermal barrier coating comprising at least one layer of a thermal barrier coating composition, wherein all of the thermal barrier coating composition in the coating-substrate system includes, by weight, between about 50% and about 85% of a dopant incorporated in the thermal barrier composition; and
exposing the thermal barrier coating to calcium-magnesium-aluminosilicate and gas turbine operating conditions;
wherein the exposing forms the calcium-magnesium-aluminosilicate penetration resistant layer;
wherein the thermal barrier coating composition includes a thermal conductivity which is at least about 30% less than the thermal conductivity of 7YSZ; and
wherein the dopant is selected from the group consisting of Yb, La, Sm, Ti, Al, InFeZnO 4 , Yb 2 O 3 , La 2 O 3 , Sm 2 O 3 , TiO 2 , Al 2 O 3 , mischmetal oxides, and combinations thereof.

Assignees

• Gen Electric

Inventors

• Schaeffer Jon Conrad
• Pabla Surinder Singh
• Dimascio Paul Stephen
• Anand Krishnamurthy
• Margolies Joshua Lee
• Parakala Padmaja

Classifications

• F01D25/005

  Selecting particular materials · CPC title

• C23C28/042 Primary

  including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides · CPC title

• F01D5/288

  Protective coatings for blades · CPC title

• F01D25/08 Primary

  Cooling (of machines or engines in general F01P); Heating; Heat-insulation (of blade-carrying members, of blades F01D5/00) · CPC title