US Patent 7960671 Laser shock processing with momentum trap

A method for laser shock processing a device, including a metallic body having a surface, comprises conformally applying a compliant solid material to the first region on the surface of the metallic body and applying a layer of ablative material to the second region on the surface of the metallic body. A damping liquid is flowed over the layer of ablative material. An array of pulses of laser energy is directed through the damping fluid to impact the layer of ablative material on the surface and peen the surface in the second region. The pulses induce pressure waves within the metallic body which propagate to the surface in the first region. The compliant solid material acts as a momentum trap, so that the acoustic waves are at least partially coupled into the compliant solid material and attenuated outside of the metallic body.