Abstract: A method for simultaneously laser shock peening opposite laser shock peening surfaces on opposite sides of an article, such as a gas turbine engine airfoil, with varying thickness using oppositely aimed laser beams and varying surface fluence of the laser beams over the laser shock peening surfaces as a function of the thickness of the article beneath each one of a plurality of laser shock peened spots formed by the beams on the surfaces. The fluence may be equal to the thickness multiplied by a volumetric fluence factor, the volumetric fluence factor being held constant over the laser shock peening surface. The volumetric fluence factor may be in a range of about 1200 J/cm3 to 1800 J/cm3 and more particularly about 1500 J/cm3. Laser beam energy may be varied with a computer program controlling firing of the laser beam.

Abstract: A laser shock peening system including a workpiece is provided. The laser shock peening system includes a workholding fixture configured to hold the workpiece. The laser shock peening system also includes a laser source configured to emit multiple laser beam pulses on the workpiece. The laser shock peening system further includes an absorptive layer disposed on the workpiece, the absorptive layer configured to absorb the laser beam pulses from the laser source into the workpiece. The laser shock peening system also includes a transparent constraining layer disposed between the laser source and the absorptive layer. The transparent constraining layer is also configured to provide a pressure medium configured to direct multiple reflected laser generated shock waves from the workpiece back into the workpiece. The laser shock peening system also includes a transducer disposed on the workholding fixture and configured to detect multiple acoustic signals emitted from the workpiece.

Abstract: A method for simultaneously laser shock peening opposite laser shock peening surfaces on opposite sides of an article, such as a gas turbine engine airfoil, with varying thickness using oppositely aimed laser beams and varying surface fluence of the laser beams over the laser shock peening surfaces as a function of the thickness of the article beneath each one of a plurality of laser shock peened spots formed by the beams on the surfaces. The fluence may be equal to the thickness multiplied by a volumetric fluence factor, the volumetric fluence factor being held constant over the laser shock peening surface. The volumetric fluence factor may be in a range of about 1200 J/cm3 to 1800 J/cm3 and more particularly about 1500 J/cm3. Laser beam energy may be varied with a computer program controlling firing of the laser beam.

Abstract: A method for laser shock peening an article, such as a gas turbine engine airfoil, with varying thickness by varying a surface fluence of a laser beam over a laser shock peening surface as a function of the thickness beneath a laser shock peened spot formed by the beam on the surface. The fluence may be equal to the thickness multiplied by a volumetric fluence factor, the volumetric fluence factor being held constant over the laser shock peening surface. The volumetric fluence factor may be in a range of about 1200 J/cm3 to 1800 J/cm3 and more particularly about 1500 J/cm3. The method may include varying energy in the laser beam using a computer program controlling firing of the laser beam. A device such as an optical attenuator external to a laser performing firing may be used to vary the energy.

Abstract: A laser shock peening system including a workpiece is provided. The laser shock peening system includes a workholding fixture configured to hold the workpiece. The laser shock peening system also includes a laser source configured to emit multiple laser beam pulses on the workpiece. The laser shock peening system further includes an absorptive layer disposed on the workpiece, the absorptive layer configured to absorb the laser beam pulses from the laser source into the workpiece. The laser shock peening system also includes a transparent constraining layer disposed between the laser source and the absorptive layer. The transparent constraining layer is also configured to provide a pressure medium configured to direct multiple reflected laser generated shock waves from the workpiece back into the workpiece. The laser shock peening system also includes a transducer disposed on the workholding fixture and configured to detect multiple acoustic signals emitted from the workpiece.