ARTICLES HAVING DAMAGE-TOLERANT THERMAL BARRIER COATING

• US 20170145836A1
• Filed: 11/24/2015
• Published: 05/25/2017
• Est. Priority Date: 11/24/2015
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Sivaramakrishnan, Shankar, Rosenzweig, Larry Steven
• Granted Patent: US 10,221,703 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 28/3215 at least one MCrAlX layer
• CPC Class Codes: C23C 28/3455 with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
• CPC Class Codes: C23C 4/073 containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements
• CPC Class Codes: C23C 4/11 Oxides
• CPC Class Codes: C23C 4/134 Plasma spraying
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: F05D 2300/2118 Zirconium oxides
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An article having a damage-tolerant thermal barrier coating includes a plurality of coating layers disposed over a substrate. The plurality of coatings comprises an inner layer and an outer layer. The outer layer is more resistant to infiltration by nominal CMAS relative to 8 weight percent yttria-stabilized zirconia at a temperature of 1300 degrees Celsius. The inner layer has, in a temperature range from about 1000 degrees Celsius to about 1200 degrees Celsius, a thermal resistance in a range from about 9×10⁻⁵ degree Kelvin per watt to about 23×10⁻⁵ degree Kelvin per watt.

Claims

1. An article comprising:

a plurality of coating layers disposed over a substrate, the plurality comprising an inner layer and an outer layer, wherein

a) the outer layer is more resistant to infiltration by nominal CMAS relative to 8 weight percent yttria-stabilized zirconia at a temperature of 1300 degrees Celsius; and

b) the inner layer has, in a temperature range from about 1000 degrees Celsius to about 1200 degrees Celsius, a thermal resistance in a range from about 9×

10<sup>−

5</sup> degree Kelvin per watt to about 23×

10<sup>−

5</sup> degree Kelvin per watt.

2. The article of claim 1, wherein the outer layer has a thickness such that the total thermal resistance of the plurality of coating layers is at least about 24 degree Kelvin per watt.

3. The article of claim 1, wherein the inner layer comprises yttria-stabilized zirconia.

4. The article of claim 3, wherein the yttria-stabilized zirconia has a yttria content in a range from about 6 weight percent to about 9 weight percent.

5. The article of claim 1, wherein the inner layer comprises stabilized hafnia, stabilized titania, or combinations thereof.

6. The article of claim 1, wherein the outer layer comprises yttria-stabilized zirconia, with a yttria content greater than 38 weight percent.

7. The article of claim 6, wherein the yttria content is at least about 55 weight percent.

8. The article of claim 1, wherein the outer layer comprises an oxide.

9. The article of claim 8, wherein the oxide comprises at least one transition metal element, at least one rare-earth element, at least one alkaline earth element, silicon, indium, aluminum, or combinations thereof.

10. The article of claim 8, wherein the oxide comprises zirconium, hafnium, titanium, or combinations thereof.

11. The article of claim 8, wherein the oxide comprises a pyrochlore.

12. The article of claim 8, wherein the oxide comprises zirconia stabilized with one or more rare earth elements.

13. The article of claim 8, wherein the oxide comprises strontium, gadolinium, and aluminum.

14. The article of claim 1, wherein the inner layer has a thickness in a range from about 200 micrometers to about 300 micrometers.

15. The article of claim 1, wherein the article comprises a turbine airfoil component or a turbine combustion component.

16. The article of claim 1, wherein the substrate comprises a superalloy.

17. An article comprising:

a plurality of coating layers disposed over a substrate, the plurality comprising an inner layer and an outer layer, wherein

the inner layer comprises yttria-stabilized zirconia and has a thickness from about 200 micrometers to about 300 micrometers; and

the outer layer comprises a material more resistant to infiltration by nominal CMAS relative to 8 weight percent yttria-stabilized zirconia at a temperature of 1300 degrees Celsius.