Robert J Mcclain

US Patent:

6914215, Jul 5, 2005

Filed:

Jun 27, 2003

Appl. No.:

10/608763

Inventors:

Brian Michael Davis - West Chester OH, US
Robert David McClain - Cincinnati OH, US
Ui Won Suh - Cincinnati OH, US
Seetha Ramaiah Mannava - Cincinnati OH, US

Assignee:

General Electric Company - Schenectady NY

International Classification:

B23K026/00

US Classification:

21912185, 21912162

Abstract:

A real time method for quality control testing of a laser shock peening process of production workpieces by analysis of natural frequency shifts during the laser shock peening process. One particular embodiment includes laser shock peening surface of the production workpiece by firing a plurality of laser beam pulses on the surface and forming a plurality of corresponding plasmas, each one of the plasmas pulses having a duration in which the plasma causes a region having deep compressive residual stresses to form beneath the surface, measuring at least one natural frequency of the workpiece for each of the laser beam pulses, calculating natural frequency shifts from a baseline natural frequency for the measured natural frequencies for at least a portion of the laser beam pulses, and using the natural frequency shifts for accepting or rejecting the workpiece with respect to pass or fail criteria.

US Patent:

20080241546, Oct 2, 2008

Filed:

Mar 30, 2007

Appl. No.:

11/694214

Inventors:

Robert David McClain - Cincinnati OH, US
Brian Michael Davis - West Chester OH, US
Seetha Ramaiah Mannava - Cincinnati OH, US

Assignee:

GENERAL ELECTRIC COMPANY - Schenectady NY

International Classification:

B23K 26/00

US Classification:

428409, 21912185

Abstract:

A method for laser shock peening an article includes laser shock peening the article forming at least one pre-stressed region having deep compressive residual stresses imparted by the laser shock peening and machining a feature into article in the pre-stressed region after the laser shock peening. The feature may be machined entirely in the pre-stressed region. The pre-stressed region may extend completely between oppositely spaced apart sides of the article with the feature machined entirely through the pre-stressed region and completely between and through the spaced apart outer and inner sides. The feature may be a hole or a scallop. The article may be an arcuate wall having a radius of curvature and the feature includes a centerline and is machined into wall with the centerline substantially parallel to the radius of curvature. The hole or scallop may have a curved sharp edge.

US Patent:

59517905, Sep 14, 1999

Filed:

Jun 26, 1998

Appl. No.:

9/107196

Inventors:

Seetharamaiah Mannava - Cincinnati OH
William D. Cowie - Xenia OH
P. Kennard Wright - Cincinnati OH
Robert D. McClain - Cincinnati OH

Assignee:

General Electric Company - Cincinnati OH

International Classification:

C21D 154

US Classification:

148510

Abstract:

A method for quality assurance of a laser process and more particularly a laser shock peening process that uses a test coupon having a deflection formed by a laser firing. The test coupon is from a metallic strip having opposite first and second sides that generally define a plane of the strip and the strip includes a laser shock peened patch of the strip that has first and second laser shock peened surfaces on the first and second sides, respectively, first and second laser shocked regions having deep compressive residual stresses imparted by the laser shock peening extending into the strip from the first and second laser shock peened surfaces, respectively, and a deflection of a portion of the strip from a position of the portion before the laser shock peening. The deflection is formed by the laser shock peening such that at least a part and preferably substantially all of the deflection lies in the plane of the strip and the test coupon preferably includes an indicating means to indicate the deflection. The quality assurance process of the present invention may further include correlating high cycle fatigue to the deflection.

US Patent:

61838829, Feb 6, 2001

Filed:

Jun 29, 1998

Appl. No.:

9/106320

Inventors:

Seetharamaiah Mannava - Cincinnati OH
William D. Cowie - Xenia OH
P. Kennard Wright - Cincinnati OH
Robert D. McClain - Cincinnati OH

Assignee:

General Electric Company - Cincinnati OH

International Classification:

B23K 2600

US Classification:

428614

Abstract:

A test coupon is formed from a metallic strip having opposite first and second sides that generally define a plane of the strip and the strip includes a laser shock peened patch of the strip that has first and second laser shock peened surfaces on the first and second sides, respectively, first and second laser shocked regions having deep compressive residual stresses imparted by the laser shock peening extending into the strip from the first and second laser shock peened surfaces, respectively, and a deflection of a portion of the strip from a position of the portion before the laser shock peening. The deflection is formed by the laser shock peening such that at least a part and preferably substantially all of the deflection lies in the plane and the test coupon preferably includes an indicating means to indicate the deflection.