System and method for laser shock peening

• US 8,222,567 B2
• Filed: 05/12/2010
• Issued: 07/17/2012
• Est. Priority Date: 05/12/2010
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Mathai, Manu, DiMascio, Paul Stephen, Della-Fera, Gabriel
• Primary Examiner(s): Nguyen, Dao H
• Application Number:
  US12/778,371
• Publication Number:
  US 20110278271A1
• Time in Patent Office: 797 Days
• Field of Search: 219/121.83, 219/121.84, 219/121.85, 219/121.6, 219/121.64, 219/128, 735/89, 356/318
• US Class Current: 219/121.85
• CPC Class Codes: C21D 10/005 by laser shock processing
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00

Abstract

A system for laser shock peening includes a laser positioned to direct a laser pulse at a first side of a work piece and a coupler on a second side of the work piece. The system further includes a Doppler shift detector positioned to measure a velocity of the coupler. A method for laser shock peening includes depositing an amount of energy from a laser pulse into a first side of a work piece and transmitting a pulse having a first frequency at a second side of the work piece. The method further includes receiving a reflected pulse having a second frequency from the second side of the work piece and determining the velocity of the work piece based on the difference between the first frequency and the second frequency.

Claims

1. A system for laser shock peening, comprising:

a. a laser positioned to direct a laser pulse at a first side of a work piece;

b. a coupler on a second side of the work piece; and

c. a Doppler shift detector positioned to measure a velocity of said coupler.

2. The system for laser shock peening as in claim 1, wherein said coupler has a coupler density and the work piece has a work piece density and said coupler density is within approximately 30 percent of the work piece density.

3. The system for laser shock peening as in claim 2, wherein said coupler density is within approximately 10 percent of the work piece density.

4. The system for laser shock peening as in claim 1, wherein said Doppler shift detector transmits a signal that is reflective of said velocity of said coupler.

5. The system for laser shock peening as in claim 4, further including a controller that receives said signal.

6. The system for laser shock peening as in claim 5, wherein said controller includes at least one predetermined limit.

7. The system for laser shock peening as in claim 1, further including a plurality of transducers positioned to receive a reflection of energy waves.

8. The system for laser shock peening as in claim 7, wherein each of said plurality of transducers transmits a timing signal.

9. The system for laser shock peening as in claim 8, further including a controller that receives said timing signal from each of said plurality of transducers.

10. A system for laser shock peening, comprising:

a. a laser positioned to direct a laser pulse at a first side of a work piece;

b. a coupler on a second side of the work piece;

c. means for amplifying a velocity of said coupler; and

d. a Doppler shift detector positioned to measure a velocity of at least a portion of said means for amplifying said velocity of said coupler.

11. The system for laser shock peening as in claim 10, wherein said Doppler shift detector transmits a signal that is reflective of said velocity of at least a portion of said means for amplifying said velocity of said coupler.

12. The system for laser shock peening as in claim 11, further including a controller that receives said signal.

13. The system for laser shock peening as in claim 12, wherein said controller includes at least one predetermined limit.

14. The system for laser shock peening as in claim 10, further including a plurality of transducers positioned to receive a reflection of energy waves.

15. The system for laser shock peening as in claim 14, wherein each of said plurality of transducers transmits a timing signal.

16. A method for laser shock peening, comprising:

a. depositing an amount of energy from a laser pulse into a first side of a work piece;

b. transmitting a pulse having a first frequency at a second side of the work piece;

c. receiving a reflected pulse having a second frequency from the second side of the work piece; and

d. determining a velocity of the work piece based on a difference between said first frequency and said second frequency.

17. The method of claim 16, further including determining said amount of energy deposited by said laser pulse into the first side of the work piece based on said velocity of the work piece.

18. The method of claim 16, further including comparing said velocity of the work piece to a predetermined value.

19. The method of claim 16, further including receiving a reflection of energy waves from said laser pulse.

20. The method of claim 19, further including determining a position of said energy deposited in the first side of the work piece based on said energy waves from said laser pulse.