Articles for high temperature service and method for making

Patent metadata

Field	Value
Publication number	US-9869188-B2
Application number	US-201414568203-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Dec 12, 2014
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

Articles having coatings that are resistant to high temperature degradation are described, along with methods for making such articles. The article comprises a coating disposed on a substrate. The coating comprises a plurality of elongated surface-connected voids. The article further includes a protective agent disposed within at least some of the voids of the coating; the protective agent comprises a substance capable of chemically reacting with liquid nominal CMAS to form a solid crystalline product outside the crystallization field of said nominal CMAS. This solid crystalline product has a melting temperature greater than about 1200 degrees Celsius. The method generally includes disposing the protective agent noted above within the surface connected voids of the coating at an effective concentration to substantially prevent incursion of CMAS materials into the voids in which the protective agent is disposed.

First claim

The invention claimed is:

1. A method, comprising:
disposing a protective agent within a plurality of elongated surface-connected voids of a coating, wherein disposing comprises infiltrating the voids with a liquid comprising a solvent and a solute dissolved in the solvent;
wherein the protective agent comprises a substance capable of chemically reacting with nominal CMAS to form a solid crystalline product outside the crystallization field of said nominal CMAS,
wherein the solid crystalline product has a melting temperature greater than about 1200 degrees Celsius,
wherein at least about 25% by volume of the porosity of the coating is occupied by the agent, and
wherein the protective agent comprises a nitride or an NZP-type material.

2. The method of claim 1 , wherein the solute comprises a precursor of the substance.

3. The method of claim 2 , further comprising reacting the precursor to form the substance.

4. The method of claim 1 , further comprising volatilizing the liquid to form a residue disposed in the voids.

5. The method of claim 1 , further comprising interposing a barrier agent between the protective agent and a substrate upon which the coating resides.

6. The method of claim 1 , wherein the protective agent is tantalum nitride.

7. The method of claim 1 , wherein the protective agent is titanium nitride.

8. The method of claim 1 , wherein the protective agent is a composition having a formula A 1-x B x Zr 4-y D y (PO4) z , wherein A and B are selected from the group consisting of alkaline earth metals and rare earth metals, D is hafnium or titanium, x is a number from 0 to 1, y is a number from 0 to 4, and z is 3 or 6.

9. The method of claim 1 , wherein the protective agent is a composition having a formula MZr 4 (PO4) 6 , wherein M includes at least one alkaline earth metal.

Assignees

• Gen Electric

Inventors

• Brosnan Kristen Hall
• Chatterjee Shahana
• Hasz Wayne Charles
• Nayak Mohandas
• Porob Digamber Gurudas
• Ramachandran Gopi Chandran
• Rosenzweig Larry Steven
• Sivaramakrishnan Shankar
• Srivastava Alok Mani
• Venkataramani Venkat Subramaniam

Classifications

• F05D2300/605

  Crystalline · CPC title

• F05D2300/228

  Nitrides · CPC title

• F01D9/02

  Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} · CPC title

• F05D2240/30

  Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor · CPC title

• C04B41/52

  Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation} · CPC title