Method for localised repair of a damaged thermal barrier

Patent metadata

Field	Value
Publication number	US-9840914-B2
Application number	US-201415115068-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Jan 29, 2014
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A method of localized repair to a damaged thermal barrier, the method including subjecting a part coated in a damaged thermal barrier to electrophoresis treatment, the part being made of an electrically conductive material, the damaged thermal barrier including a ceramic material and presenting at least one damaged zone that is to be repaired, the part being present in an electrolyte including a suspension of particles in a liquid medium, the ceramic coating being deposited by electrophoresis in the damaged zone in order to obtain a repaired thermal barrier for use at temperatures higher than or equal to 1000° C., the particles being made of a material different from the ceramic material present in the damaged thermal barrier.

First claim

The invention claimed is:

1. A method of localized repair to a damaged thermal barrier, the method comprising:
a) subjecting a part coated by a damaged thermal barrier to electrophoresis treatment, the part being made of an electrically conductive material, the damaged thermal barrier comprising a ceramic material and having a columnar structure, the damaged thermal barrier presenting at least one damaged zone that is to be repaired, the part being present in an electrolyte comprising a suspension of particles in a liquid medium, the particles in a non-agglomerated state having a mean size lying in the range from 20 nm to 1 μm, a ceramic coating being deposited by electrophoresis in the damaged zone in order to obtain a repaired thermal barrier for use at temperatures higher than or equal to 1000° C., the particles being made of a material different from the ceramic material present in the damaged thermal barrier,
wherein prior to step a), the method includes a step of forming the particles by performing a sol-gel method, said sol-gel method comprising a supercritical drying of a liquid precursor to form the particles.

2. A method according to claim 1 , wherein before the beginning of step a), the particles are present in the liquid medium at a concentration greater than or equal to 0.1 g/L.

3. A method according to claim 1 , wherein the duration of step a) is greater than or equal to 1 minute.

4. A method according to claim 1 , wherein a voltage greater than or equal to 1 V is imposed during all or part of step a) between the part and a counter electrode.

5. A method according to claim 1 , wherein a thickness e of the deposited ceramic coating is greater than or equal to 30 μm.

6. A method according to claim 1 , wherein the part is coated by an attachment layer enabling the thermal barrier to attach to the part, and wherein the ceramic coating is deposited on the attachment layer.

7. A method according to claim 1 , wherein prior to step a), the damaged zone is subjected to a stripping step.

8. A method according to claim 1 , wherein after step a), the method includes a step b) of consolidation by subjecting the deposited ceramic coating to heat treatment.

9. A method according to claim 1 , wherein the part constitutes a turbine engine blade.

10. A method of localized repair to a damaged thermal barrier, the method comprising:
a) subjecting a part coated by a damaged thermal barrier to electrophoresis treatment, the part being made of an electrically conductive material, the damaged thermal barrier comprising a ceramic material and having a columnar structure, the damaged thermal barrier presenting at least one damaged zone that is to be repaired, the part being present in an electrolyte comprising a suspension of particles in a liquid medium, the particles in a non-agglomerated state having a mean size lying in the range from 20 nm to 1 μm, a ceramic coating being deposited by electrophoresis in the damaged zone in order to obtain a repaired thermal barrier for use at temperatures higher than or equal to 1000° C., the particles being made of a material different from the ceramic material present in the damaged thermal barrier,
wherein a generator imposes a potential difference between the part and a counter electrode during the electrophoresis treatment, the generator generating a pulsed current during the electrophoresis treatment.

11. A method according to claim 10 , wherein before the beginning of step a), the particles are present in the liquid medium at a concentration greater than or equal to 0.1 g/L.

12. A method according to claim 10 , wherein the duration of step a) is greater than or equal to 1 minute.

13. A method according to claim 10 , wherein a voltage greater than or equal to 1 V is imposed during all or part of step a) between the part and a counter electrode.

14. A method according to claim 10 , wherein a thickness e of the deposited ceramic coating is greater than or equal to 30 μm.

15. A method according to claim 10 , wherein the part is coated by an attachment layer enabling the thermal barrier to attach to the part, and wherein the ceramic coating is deposited on the attachment layer.

16. A method according to claim 10 , wherein prior to step a), the damaged zone is subjected to a stripping step.

17. A method according to claim 10 , wherein after step a), the method includes a step b) of consolidation by subjecting the deposited ceramic coating to heat treatment.

18. A method according to claim 10 , wherein the part constitutes a turbine engine blade.

19. A method according to claim 10 , wherein the counter electrode is made of platinum.

20. A method of claim 10 , wherein the ceramic coating being deposited by electrophoresis in the damaged zone covers an entire surface of the damaged zone.

Assignees

• Safran Aircraft Engines
• Centre Nat Rech Scient
• Institut Nat Polytechnique
• Univ Paul Sabatier—Toulouse Iii

Inventors

• MALIE ANDRé HUBERT LOUIS
• Hamadi Sarah
• Ansart Florence
• Bonino Jean-Pierre
• Cerda Hélène
• Pujol Guillaume

Classifications

• F05D2300/5023

  Thermal capacity · CPC title

• C25D13/12

  characterised by the article coated · CPC title

• F05D2230/30

  with deposition of material · CPC title

• F05D2230/90

  Coating; Surface treatment · CPC title

• F05D2230/40

  Heat treatment · CPC title