Environmental barrier coating

Patent metadata

Field	Value
Publication number	US-12065382-B2
Application number	US-202117314670-A
Country	US
Kind code	B2
Filing date	May 7, 2021
Priority date	May 7, 2021
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.

First claim

What is claimed is:

1. An environmental barrier coating, comprising:
a barrier layer, the barrier layer including a matrix, diffusive particles, and gettering particles; and
a calcium-magnesia alumina-silicate (CMAS)-resistant component, wherein the CMAS-resistant component includes hafnium silicate and a rare earth hafnate, wherein the rare earth hafnate is La-hafnate, Nd-hafnate or Pr-hafnate.

2. The environmental barrier coating of claim 1 , wherein the CMAS-resistant component includes a glass component.

3. The environmental barrier coating of claim 1 , wherein the CMAS-resistant component includes at least 20 mole percent rare earth metal cations.

4. The environmental barrier coating of claim 1 wherein the rare earth hafnate is selected such that when the solubility limit of the rare earth hafnate in monoclinic hafnia is exceeded, a pyrochlore phase is formed.

5. The environmental barrier coating of claim 1 , wherein the CMAS-resistant component further includes hafnia.

6. The environmental barrier coating of claim 5 , wherein the CMAS-resistant component includes about 40 single cation mole percent hafnium oxide, about 20 single cation mole percent hafnium silicate, and about 40 single cation mole percent rare-earth hafnate.

7. The environmental barrier coating of claim 5 , wherein the CMAS-resistant component includes between about 60 and about 90 single cation mole percent hafnium silicate, between about 5 and about 40 single cation mole percent rare-earth hafnate, and up to about 5 single cation mole percent hafnium oxide.

8. The environmental barrier coating of claim 5 , wherein the CMAS-resistant component includes between about 5 and about 20 single cation mole percent hafnium silicate, between about 40 and about 90 single cation mole percent rare-earth hafnate, and up to about 5 single cation mole percent hafnium oxide.

9. The environmental barrier coating of claim 5 , wherein the CMAS-resistant component includes about 31 single cation mole percent hafnium silicate, about 66 single cation mole percent rare-earth hafnate, and about 3 single cation mole percent hafnium oxide.

10. An article, comprising:
a substrate; and
a coating disposed on the substrate, the coating including
a barrier layer, the barrier layer including a matrix, diffusive particles, and gettering particles, and
a CMAS-resistant component, the CMAS-resistant component including a mixture of hafnium silicate and a rare-earth hafnate, wherein the CMAS-resistant component includes at least 20 mole percent rare earth hafnate, wherein the rare earth hafnate is La-hafnate, Nd-hafnate or Pr-hafnate.

11. The article of claim 10 , wherein the substrate is a CMC-based material.

12. The article of claim 10 , wherein a ratio of a coefficient of thermal expansion of the CMAS-resistant component and a coefficient of thermal expansion of the substrate is between about 0.95 to about 1.6.

13. The article of claim 10 , wherein the CMAS-resistant component includes about 40 single cation mole percent hafnium oxide, about 20 single cation mole percent hafnium silicate, and about 40 single cation mole percent rare-earth hafnate.

14. The article of claim 10 , wherein the CMAS-resistant component includes between about 60 and about 90 single cation mole percent hafnium silicate, between about 5 and about 40 single cation mole percent rare-earth hafnate, and up to about 5 single cation mole percent hafnium oxide.

15. The article of claim 10 , wherein the CMAS-resistant component includes between about 5 and about 20 single cation mole percent hafnium silicate, between about 40 and about 90 single cation mole percent rare-earth hafnate, and up to about 5 single cation mole percent hafnium oxide.

16. A method of fabricating an article, comprising:
applying a barrier layer on a substrate, the barrier layer including a matrix, diffusive particles, gettering particles, and a CMAS-resistant component, the CMAS-resistant component including hafnium silicate and a rare earth hafnate, wherein the rare earth hafnate is La-hafnate, Nd-hafnate or Pr-hafnate.

17. The method of claim 16 , wherein the applying is by thermal spray.

Assignees

• Rtx Corp

Inventors

• Jackson Richard Wesley
• Beals James T
• Tang Xia
• Litton David A
• Zaleski Elisa M
• Hazel Brian T

Classifications

• C23C4/10

  Oxides, borides, carbides, nitrides or silicides; Mixtures thereof · CPC title

• C04B2235/9669

  Resistance against chemicals, e.g. against molten glass or molten salts · CPC title

• C04B2235/3427

  Silicates other than clay, e.g. water glass · CPC title

• C04B2235/3248

  Zirconates or hafnates, e.g. zircon · CPC title

• C23C4/134

  Plasma spraying · CPC title