Lsp Technologies, Inc.

Other

Battelle Memorial Institute

Battelle Development Corporation

L&p Technologies, Inc.

Allan H Clauer

Jeff L Dulaney

Steven M Toller

Jeffrey L Dulaney

David F Lahrman

David W Sokol

Mark E O'Loughlin

Craig Thompson Walters

Steve Toller

Harold M Epstein

Richard D Tenaglia

Steven E Dykes

Robert W Baumgarten

Bernerd E Campbell

Barry P Fairand

Benjamin R Hack

Boyd A Mueller

Stephen C Ford

David F Lahram

Jerry G Weinstein

David F Lahrmann

Joseph F Clarady

Methods, systems, and apparatuses are disclosed for temporal pulse shaping of laser pulses used in laser shock peening applications. In one embodiment, a system for temporal pulse shaping of a laser beam used for laser shock peening comprises a laser; a modulator; a high voltage driver, a waveform generator, a polarizer, and an optical amplifier.

Temporal pulse shaping for laser shock peening

Methods, systems, and apparatuses are disclosed for temporal pulse shaping of laser pulses used in laser bond inspection applications.

Temporal pulse shaping for laser bond inspection

A bend bar is available for use in a quality control test for testing for a consistency of residual stress effects in a particular material using a given a laser peening process. The bar is composed of the particular material to be tested and has a bar length and a bar thickness. The particular material has a characteristic maximum stress penetration depth for compressive residual stresses that can be formed in using the given laser peening process. The bar thickness is chosen so as to be at least twice the characteristic maximum stress penetration depth. The bar has a test surface that extends parallel to the bar length and perpendicular to the bar thickness. After forming a spot pattern on the test surface using the given laser peening process, the deflection generated in the bar due to the compressive residual stresses induced by laser peening can then be measured and used as a quality control measurement.

Bend bar quality control method for laser shock peening

A method of manufacturing a workpiece involves performing any one of various post-processing part modification steps on a workpiece that has been previously subjected to laser shock processing. In one step, material is removed from the compressive residual stress region of the processed workpiece. Alternately, the workpiece may be provided with oversized dimensions such that the removal process removes an amount of material sufficient to generate a processed workpiece having dimensions substantially conforming to design specifications. Alternately, the material removal process is adapted to establish a penetration depth for material removal that coincides with the depth at which the workpiece exhibits maximum compressive residual stress. Alternately, a first high-intensity laser shock processing treatment is performed on the workpiece, followed by the removal of material from the compressive residual stress region, and then a second low-intensity laser shock processing treatment is performed on the workpiece. Material may be removed from the compressive residual stress region through a workpiece surface different from the laser shock processed surface. Material may also be deposited onto the laser shock processed surface.

Method of modifying a workpiece following laser shock processing

A laser peening apparatus is available for laser peening a hidden surface of a workpiece, the hidden surface not being line-of-sight accessible to laser energy for treatment thereof. The apparatus includes a pulsed laser system and a laser directing unit. The pulsed laser system is configured for generating the laser energy used for laser peening. The laser directing unit operatively receives and channels the laser energy generated by the pulsed laser system. The laser directing unit includes a laser transmission end and is capable of variably and selectively positioning that laser transmission end. The laser directing unit is thereby configured for variably and selectively directing laser energy upon the hidden surface via the laser transmission end.

Laser peening of dovetail slots by fiber optical and articulate arm beam delivery

Various laser shock processing methods are provided to establish selective compressive residual stress distribution profiles within a workpiece. An asymmetrical stress distribution profile may be formed through the thickness of a thin section of a gas turbine engine airfoil. One method involves simultaneously irradiating a workpiece with a set of laser beams to form a corresponding set of adjacent non-overlapping laser shock peened surfaces, enabling the shockwaves to encounter one another. Additionally, opposite sides of the workpiece may be irradiated at different times to form opposing laser shock peened surfaces, enabling the shockwaves to meet at a location apart from the mid-plane. Furthermore, opposite sides of the workpiece may be irradiated simultaneously using laser beams having different pulse lengths to form opposing laser shock peened surfaces. Moreover, opposite sides of the workpiece may be irradiated simultaneously to form a set of laterally offset laser shock peened surfaces.

Method using laser shock processing to provide improved residual stress profile characteristics

The present invention enables the processing head to locate itself precisely on the surface of the structure being processed, and to then reposition itself correctly for the next laser spot. Further, the present invention will complete processing a laser peened area, the area including a multiplicity of spots arranged in a specific pattern, and correctly laser peen each spot in the area under control of a controller including control linkages with the laser. The invention further provides an automated laser peening processing head encompassing spatial position sensing and locating means, as well as programmed spatial positioning, application of overlay materials, verification of proper overlay condition and positioning, and notification of the laser to pulse the surface of the structure.

Automated positioning of mobile laser peening head

A method of controlling the application of laser peening overlays on the surface of a workpiece to reduce the variability of shock waves generated therein, comprises applying an energy-absorbing overlay to a portion of the surface of a workpiece, measuring the thickness of the energy-absorbing overlay in at least one location on the energy-absorbing overlay, applying a transparent overlay material over the energy-absorbing overlay, measuring the thickness of the transparent overlay in at least one location on the transparent overlay, determining if the measured values for each overlay is within a specified range, and directing a pulse of coherent energy to the workpiece to create a shock wave therein when the measured values are within the specified range.

Overlay control for laser peening

Various laser shock processing systems are provided to establish selective compressive residual stress distribution profiles within a workpiece. An asymmetrical stress profile may be formed through the thickness of a thin section of a gas turbine engine airfoil. One system is configured to simultaneously irradiate a workpiece with a set of laser beams to form a corresponding set of adjacent non-overlapping laser shock peened surfaces, enabling the shockwaves to encounter one another. Another system irradiates opposite sides of the workpiece at different times to form opposing laser shock peened surfaces, enabling the shockwaves to meet at a location apart from the mid-plane. Another system simultaneously irradiates opposite sides of the workpiece using laser beams having different pulse lengths to form opposing laser shock peened surfaces. Another system simultaneously irradiates opposite sides of the workpiece to form a set of laterally offset laser shock peened surfaces.

System for laser shock processing objects to produce enhanced stress distribution profiles

Articles produced by laser shock processing exhibit various compressive residual stress distribution profiles. A gas turbine engine airfoil includes an asymmetrical stress profile formed through the thickness of its thin section. The articles include plural laser shock peened surfaces and plural regions having deep compressive residual stresses imparted by laser shock peening extending into the article from the laser peened surfaces. One article includes at least one set of simultaneously formed, adjacent non-overlapping laser shock peened surfaces. Another article includes at least one set of opposing laser shock peened surfaces formed at different times at opposite sides of the article. Another article includes at least one set of opposing laser shock peened surfaces formed simultaneously at opposite sides of the article using laser beams having different pulse lengths. Another article includes at least one set of laterally offset laser shock peened surfaces simultaneously formed at opposite sides of the article.

Articles having improved residual stress profile characteristics produced by laser shock peening

A method and apparatus for increasing the effectiveness and efficiency of laser shock processing of a solid material. The method includes applying an energy absorbing coating to a portion of the surface of a solid material, applying an ultraviolet curable resin to the coated portion of the surface of the solid material, applying an ultraviolet light to the curable resin to form a pellicle over the energy absorbing coating on the surface of the solid material, and applying a transparent overlay to the pellicular portion of the solid material. A pulse of coherent laser energy is directed to the coated portion of the solid material to create a shockwave. After the pulse of coherent energy is directed to the solid material, a high-speed jet of fluid may be directed to the coated portion of the solid material to remove the remaining coating from the solid material.

UV curable overlays for laser peening

An image processing system for monitoring a laser peening process includes a laser peening system having a workpiece positioner and a system controller. A video camera is utilized for forming an electronic image of at least a portion of a workpiece. An image processing computer is connected to the video camera, and the laser peening controller includes a program to determine a position of the workpiece.

Growing community of inventors

Worthington, OH, United States of America

Allan H Clauer