Abstract: An apparatus and method of utilizing natural frequency shifts of a laser shock processed workpiece to determine if sufficient laser shock processing has been accomplished.

Abstract: An apparatus for measuring the strength of a pressure pulse created from a laser peening device. The apparatus is reusable, and includes a pressure-sensitive medium, a back-up disk, and a cap, all disposed within a housing having a removable lid. All components of the apparatus are replaceable, thereby allowing an operator to utilize the apparatus more than once despite the harsh environment of laser peening.

Abstract: A monitor of a plurality of optical signals utilizing fiber optics which form an array. An image of the array is captured and the captured image is processed for detecting a quality of an optical signal such as the presence, absence, intensity, wavelength, or other quality of the optical signal. A method of monitoring a plurality of optical signals by capturing a plurality of optical signals from an array of signals and detecting a quality of at least one optical signal is also disclosed.

Abstract: A laser amplifier for laser shock processing having a pump cavity supplying photons at selected or variable wavelengths and orientations to that of the gain medium present therein. In one embodiment, the pump wavelength is substantially equal to a corresponding wavelength difference between the upper laser state energy level and the ground state energy level of atoms composing the gain medium. In an alternate embodiment, photonic energy is applied asymmetrically to the gain medium to produce a desired spatial energy profile. The pump cavity may comprise an alexandrite laser or a diode laser system. Depending on the type of pump cavity, the photonic energy is applied to the gain medium either longitudinally or transverse to the laser beam axis of traversing therein.

Abstract: A technique for increasing the lifetime of optical components that are used in a laser for laser shock peening. The technique employs a properly sized iris or a gradient reflector within a laser oscillator to produce a single-transverse-mode laser beam. This technique eliminates hot spots that significantly reduce the lifetime of optical components. Utilization of the present invention can increase the lifetime of components by a factor of ten of their conventional lifetime.

Abstract: An apparatus and method for providing a substantially debris-free laser beam path for use during laser shock processing. The method and apparatus include a system for removing debris from the laser beam path and a system for preventing debris from entering the laser beam path.

Abstract: 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.

Abstract: A multiple laser peening cell apparatus for receiving pulses of energy from a laser shock peening device is comprised of a first cell for receiving a first pulse of energy, a second cell for receiving a second pulse of energy, and a beam distribution means, for directing the first pulse of energy and the second pulse of energy. Also, a method of directing pulses of energy originating from a single source to multiple workpieces comprises the steps of creating a first pulse of energy, directing the first pulse of energy to a first workpiece located in a first laser peening cell, creating a second pulse of energy, and directing the second pulse of energy to a second workpiece located in a second laser peening cell.

Abstract: A remote laser shock processing system for improving the properties of a solid workpiece by providing shock waves therein. The system includes a remote output end and a laser beam delivery arrangement for directing a beam of coherent energy to a specific location along a workpiece. In addition, a method of utilizing the remote laser shock processing system is included.

Abstract: A method and apparatus for improving the functionality, quality, and usefulness of a beam of coherent energy used in laser shock processing by utilizing an apodizer within the oscillator or amplifier of a laser. The apodizer used may be a phase plate, a serrated aperture, a birefringent beam shaper, an absorbent graded aperture, a reflective graded aperture, or a combination thereof. A method and apparatus for reducing or preventing damage to an oscillator and an amplifier utilizes an apodizer.

Abstract: A method and apparatus for quality control of laser shock processing. The method includes measuring emissions and characteristics of a workpiece when subjected to a pulse of coherent energy from a laser. These empirically measured emissions and characteristics of the workpiece are correlated to theoretical shock pressure, residual stress profile, or fatigue life of the workpiece. The apparatus may include a radiometer or acoustic detection device for measuring these characteristics.

Abstract: A method is disclosed for repairing damage to an airfoil. The method provides for the removal of a section of the airfoil that substantially encompasses the damaged area, which consequently leaves a void and a cut-away surface in the airfoil. A replacement piece larger than the residual void is provided for use in replacing the section removed from the airfoil. A joining operation welds or otherwise joins the replacement piece to the airfoil at the cut-away surface to form a joined airfoil. The joined airfoil has a seam between the airfoil and the replacement piece. At least a portion of the seam is processed by laser shock peening to induce compressive residual stresses therein.

Abstract: The invention relates to a method and apparatus for improving properties of a solid material by providing shockwaves therethrough. The method includes controlling the incident angle &THgr; of the laser beam applied to the workpiece so that the required residual stresses are created in the workpiece. Particular methods of control such as lenses, polarizers, and particular transparent overlay geometries are shown. The apparatus includes structure for controlling the position and incident angle of the laser beam then controlling the polarization and/or the shape of the incident impact area, based on such incident angle &THgr; or thickness of the workpiece.

Abstract: A method of altering the properties of a solid material by varying the temperature of the solid material either before or after or both before and after laser shock processing the solid material. In addition, the method may be repeated for successive laser shock processing of the solid material.

Abstract: A laser shock processing apparatus with controller for controlling laser shock processing operation. The controller generates an operator perceivable alert when a processing value is not within a predetermined range of a preset value. The controller may adjust the processing value to be within the predetermined range or may deactivate a laser from directing a beam of coherent energy to a workpiece. In one embodiment, a plurality of controllers comprise distributed processing of various processing values for controlling laser shock processing operation.

Abstract: A method of laser shock peening a workpiece including the steps of laser shock peening at least one surface of the workpiece so that it extends over an area of the workpiece and forms a region having compressive residual stresses imparted by the laser shock peening extending into the workpiece from the surface, and firing a laser beam to produce the laser shock peened surface with more than one row of laser beam spots, wherein adjacent laser beam spots and/or rows are one of touching or spaced apart from each other.

Abstract: An apparatus creating a processing cell for laser peening operations includes an enclosure which substantially defines a work cell or processing cell with a transparent overlay material applicator disposed therein. A cleaning system is utilized that may include a vapor exhaust, liquid removal system, and a gas or air supply. A vapor exhaust system is connected to the enclosure for removing vapor from within the processing cell. A liquid removal system is connected to the enclosure for removing liquid from the processing cell. A gas or air supply is connected to the enclosure to flood the enclosure with gas or air to flush airborne debris therefrom. A workpiece manipulator may be disposed or operate within the cell for moving workpieces therein.

Abstract: A hollow workpiece includes an outside surface through which a port opens to the hollow interior, and a laser peened area on the surface of the workpiece. The laser peened area is created on the surface while the hollow interior is at least partially filled with a substance other than air. A method of laser peening a hollow core gas turbine engine blade includes the steps of providing a hollow core gas turbine engine blade, filling the hollow core with a substance other than air, and then, laser peening the hollow core gas turbine engine blade.

Abstract: An apparatus creating a processing cell for laser peening operations includes an enclosure which substantially defines a work cell or processing cell with a transparent overlay material applicator located therein. A cleaning system is utilized that may include a vapor exhaust, liquid removal system, and a gas or air supply. A vapor exhaust system is connected to the enclosure for removing vapor from within the processing cell. A liquid removal system is connected to the enclosure for removing liquid from the processing cell. A gas or air supply is connected to the enclosure to flood the enclosure with gas or air to flush airborne debris therefrom. A workpiece manipulator may be disposed or operate within the cell for moving workpieces therein.

Abstract: The present invention provides a method of laser shock processing that can be used in a production environment that increases the peak pressure of the shock wave applied to the workpiece that increases residual compresses stresses therein. Such improvement is created by a reduction of dielectric breakdown of the transparent overlay layer utilized.The method includes the steps of applying a transparent overlay such as water over the workpiece and reducing or limiting the thickness of the transparent overlay material. An alternate embodiment of the invention to reduce dielectric breakdown incorporates the use of a changing or circularly polarized laser beam as opposed to a linearly polarized laser beam.