Method for cleaning and stripping a turboshaft engine blade using a pulsed laser

• US 9,415,462 B2
• Filed: 05/02/2012
• Issued: 08/16/2016
• Est. Priority Date: 05/02/2011
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma (Safran SA)
• Inventors: Hugot, Juliette, Bourdin, Franck, Fevrier, Thierry, Gestin, Jerome
• Primary Examiner(s): Chang, Richard
• Application Number:
  US14/114,836
• Publication Number:
  US 20140082939A1
• Time in Patent Office: 1,567 Days
• US Class Current: 1/1
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/52 Ceramics
• CPC Class Codes: B23K 26/0006 taking account of the properties of the material involved B23K26/32, B23K26/40 take precedence
• CPC Class Codes: B23K 26/3568 Modifying rugosity
• CPC Class Codes: B23K 26/3584 Increasing rugosity, e.g. roughening
• CPC Class Codes: B23K 26/361 for deburring or mechanical trimming B23K26/351 takes precedence
• CPC Class Codes: B23K 26/362 Laser etching
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: F01D 25/002 Cleaning of turbomachines
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F01D 5/284 Selection of ceramic materials
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: F05D 2230/13 using lasers
• CPC Class Codes: F05D 2230/90 Coating; Surface treatment
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling

Abstract

A method for cleaning a turboshaft engine blade comprising a superalloy body covered with a coating, in which the coating of the blade is at least partially machined using a pulsed laser. At least the feed rate of the pulsed laser and the pulse frequency of the pulsed laser are parameterized such that the machined surface of the blade has a roughness of 4 μm to 10 μm.

Claims

1. A method for cleaning and stripping a turboshaft engine blade comprising a superalloy body covered with a coating, comprising:

identifying a portion of the coating to remove, the coating including a metal layer covering the body of the blade and an external ceramic layer covering the metal layer; and

machining, at least partially, the coating of the blade using a pulsed laser to remove at least the external ceramic layer of the coating,

wherein a feed rate of the pulsed laser and a pulse frequency of the pulsed laser are parameterized such that a machined surface of the blade has a roughness of 4 μ

m to 10 μ

m.

2. The method according to claim 1, wherein the pulsed laser is parameterized in order to remove only the external ceramic layer.

3. The method according to claim 1, wherein the pulsed laser is parameterized in order to remove only the external ceramic layer and the metal layer.

4. The method according to claim 1, wherein the pulsed laser is parameterized in order to remove the entire coating of the blade.

5. The method according to claim 1, wherein the feed rate of the pulsed laser is between 25 mm/s and 1000 mm/s.

6. The method according to claim 5, wherein the feed rate of the pulsed laser is between 100 mm/s and 600 mm/s.

7. The method according to claim 1, wherein the pulse frequency of the pulsed laser is between 12 kHz and 50 kHz.

8. The method according to claim 7, wherein the pulse frequency of the pulse laser is less than or equal to 16 kHz.

9. The method according to claim 1, wherein the roughness is constant over the machined coating.

10. The method according to claim 1, wherein the coating comprises a plurality of layers, the pulsed laser machines the layers of the coating by carrying out a plurality of machining passes, and the number of machining passes for a layer is defined as a function of a thickness of the layer and a hardness of a material of the layer.

11. The method according to claim 1, wherein the pulsed laser is moved along machining lines on the coating, and two consecutive machining lines overlap.

12. The method according to claim 1, wherein a controller moves the pulsed laser in the course of the machining along a defined trajectory based on three-dimensional modeling of the blade to be cleaned.

13. The method according to claim 1, wherein the superalloy body of the blade is not removed by the machining.

14. The method according to claim 1, wherein a width of the pulsed laser is less than or equal to 0.05 mm.

15. The method according to claim 1, wherein the metal layer has a thickness between 50 and 100 μ

m and the external ceramic layer has a thickness between 150 and 350 μ

m.