Component repair using brazed surface textured superalloy foil

Patent metadata

Field	Value
Publication number	US-9782862-B2
Application number	US-201414768136-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A superalloy component such as a gas turbine engine blade ( 40 ) having a ceramic thermal barrier coating ( 41 ) is repaired using a textured repair foil ( 30 ). A degraded region of the thermal barrier coating is removed ( 14 ) and the underlying superalloy material surface is prepared ( 16 ) for re-coating. The repair foil is includes a layer of boron-free braze material ( 34 ) and a layer of superalloy material ( 32 ) having a textured surface ( 36 ). The foil is brazed ( 18 ) to the prepared surface during a solution heat treatment effective to homogenize the braze ( 20 ). A new area of thermal barrier coating ( 46 ) is applied over the foil with a bond that is enhanced by the texturing of the foil surface.

First claim

The invention claimed is:

1. A method comprising:
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying a foil to the repair area, the foil comprising a layer of alloy material and a layer of braze material, the braze material being placed in contact with the underlying superalloy substrate material;
wherein the layer of alloy material comprises a layer of superalloy material adjacent the braze material and a layer of bond coat material on the layer of superalloy material; and
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the bond coat material.

2. A method comprising:
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying a foil to the repair area, the foil comprising a layer of alloy material and a layer of braze material on a side of the alloy material, the braze material being placed in contact with the underlying superalloy substrate material;
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the alloy material;
wherein the braze material comprises a ternary alloy comprising a composition in wt. % of: Cr 15-25%; Ti 15-25%; balance Ni.

3. A method comprising:
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying a foil to the repair area, the foil comprising a layer of alloy material and a layer of braze material on a side of the alloy material, the braze material being placed in contact with the underlying superalloy substrate material;
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the alloy material;
wherein the braze material comprises a composition in wt. % within the following ranges:
Cr 12-16%;
Ti 13-16%;
Al 0-2.5%;
Co 2-4%;
W 3-5%;
Mo 0-2%;
Ta 0-2%;
balance Ni.

4. A method comprising:
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying a foil to the repair area, the foil comprising a layer of alloy material and a layer of braze material on a side of the alloy material, the braze material being placed in contact with the underlying superalloy substrate material;
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the alloy material;
wherein the braze material comprises a composition in wt. % within the following ranges:
Cr 15-18%;
Ti 10-15%;
Al 0-2.5%;
Co 2-4%;
W 3-5%;
Mo 0-2%;
Ta 0-2%;
balance Ni.

5. A method comprising:
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying a foil to the repair area, the foil comprising a layer of alloy material and a layer of braze material on a side of the alloy material, the braze material being placed in contact with the underlying superalloy substrate material;
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the alloy material;
wherein the braze material comprises a composition in wt. % within the following ranges:
Cr 15-19%;
Ti 8-10%;
Al 0-2.5%;
Co 14-18%;
Mo 12-16%;
balance Ni.

6. A method comprising:
preparing a foil comprising a layer of alloy material and a layer of braze material;
creating irregularities on a surface of the alloy material opposed the layer of braze material by one of an etching process, a casting process, or a spark plasma sintering process;
removing a degraded portion of a thermal barrier coating from a repair area of a component to reveal an underlying superalloy substrate material;
applying the foil to the repair area, the braze material being placed in contact with the underlying superalloy substrate material;
attaching the foil to the component with a braze heat treatment; and
applying a new thermal barrier coating onto the surface of the alloy material over the irregularities.

Assignees

• Siemens Energy Inc

Inventors

• Kamel Ahmed
• Jouini Dhafer
• Merrill Gary B
• Ozbaysal Kazim

Classifications

• B23K1/0018

  Brazing of turbine parts · CPC title

• B23K35/3033

  Ni as the principal constituent · CPC title

• C22F1/18

  High-melting or refractory metals or alloys based thereon · CPC title

• Y10T428/12438

  Composite · CPC title

• B23K35/0238

  layered · CPC title