Method for repairing turbine component by application of thick cold spray coating

Patent metadata

Field	Value
Publication number	US-10315218-B2
Application number	US-201715642622-A
Country	US
Kind code	B2
Filing date	Jul 6, 2017
Priority date	Jul 6, 2017
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A method for repairing a Ni-based alloy component includes preparing a surface of the Ni-based alloy component for receiving a cold spray repair; spraying a stream of particles onto a the surface of the Ni-based alloy component to form a coating thereon; and removing any over-spray on the surface of the Ni-based alloy component. The particles are formed from an alloy material having a melting point such that the particles are sprayed at a spray temperature that is less than the melting point of the alloy material.

First claim

What is claimed is:

1. A method of repairing a Ni-based alloy component, the method comprising:
preparing a surface to be repaired of the Ni-based alloy component for receiving a cold spray repair, wherein the surface to be repaired has a damaged portion that includes a defect therein, wherein the defect extends about 1.5 mm to about 6 mm into the surface of the Ni-based alloy component;
spraying Ni-based alloy particles carried by a high pressure gas stream onto the surface of the Ni-based alloy component to form a coating within the defect of the damaged portion of the surface, wherein the Ni-based alloy particles have a melting point; and wherein the Ni-based alloy particles are sprayed at a spray temperature that is less than the melting point of the Ni-based alloy particles, and wherein the spray temperature is about 500° C. to about 1100° C.;
removing any over-spray on the surface of the Ni-based alloy component;
solution heat treating the coating on the surface of the Ni-based alloy component, wherein heat treating the coating comprises heating the coating to a heat treatment temperature of about 900° C. to about 1300° C. for a period of about 30 minutes to about 5 hours; and
after solution heat treating the coating, quenching the coating from the heat treatment temperature to a temperature that is less than a gamma-prime temperature and a gamma-double prime solvus temperature of the Ni-based alloy particles such that a matrix phase of gamma nickel and gamma-prime primary precipitate is present in the coating.

2. The method of claim 1 , wherein the coating has a thickness of about 1.5 mm to about 6 mm within the defect.

3. The method of claim 1 , wherein the coating has a thickness of about 2.5 mm to about 5 mm within the defect.

4. The method of claim 1 , wherein the coating has a thickness of about 3.0 mm to about 5 mm within the defect.

5. The method of claim 1 , wherein the Ni-based alloy particles are sprayed at a spray temperature of about 650° C. to about 800° C.

6. The method of claim 1 , wherein the high pressure gas stream is selected from the group consisting of helium gas, nitrogen gas, atmospheric air, argon, and mixtures thereof.

7. The method of claim 1 , wherein the Ni-based alloy particles have a composition identical to the Ni-based alloy component as originally formed.

8. The method of claim 1 , wherein the Ni-based alloy particles have an average size of about 1 μm to about 100 μm.

9. The method of claim 1 , wherein the Ni-based alloy particles have an average size of about 5 μm to about 50 μm.

10. The method of claim 1 , wherein the coating has a tensile strength that is about 100% to about 130% of the tensile strength of the original Ni-based alloy component, and wherein the coating has a porosity of about 5% or less after heat treatment.

11. The method of claim 1 , wherein preparing a surface to be repaired comprises removing an existing material or layer from the surface so that the coating is formed directly on the Ni-based alloy material of the Ni-based alloy component so as to bond directly thereto.

12. The method of claim 1 , wherein the coating fills the defect to restore the surface of the Ni-based alloy component.

13. The method of claim 1 , spraying the Ni-based alloy particles onto the surface of the Ni-based alloy component to form the coating restores the component to its original dimensions.

14. The method of claim 1 , wherein spraying the Ni-based alloy particles onto the surface of the Ni-based alloy component to form the coating within the defect of the damaged portion of the surface, comprises spraying multiple streams of Ni-based alloy particles onto the surface of the Ni-based alloy component to form the coating within the defect of the damaged portion of the surface.

15. The method of claim 1 , wherein the coating comprises a hybrid coating having a combination of materials.

16. The method of claim 1 , wherein the coating comprises a graded coating composition.

17. The method of claim 1 , further comprising:
intermittently changing from the Ni-based alloy particles to a second particle feedstock during the spraying the stream.

Assignees

• Gen Electric

Inventors

• Mahalingam Anantharaman
• Manogharan Prabhakaran
• Thimmegowda Shalini
• Calla Eklavya
• Ramachandran Gopi Chandran

Classifications

• C23C28/022

  with at least one MCrAlX layer · CPC title

• B05D2202/40

  based on other transition elements · CPC title

• C23C24/04 Primary

  Impact or kinetic deposition of particles · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• C23C30/005

  on hard metal substrates · CPC title