Abstract: A method of applying thermal barrier coating systems to a metal piece having a cooling hole extending along a central axis through the piece from a first surface of the piece to a second surface of the piece opposite the first surface. The method includes spraying a bond coat on the first surface of the piece and spraying a thermal barrier coating on the bond coat. Further, the method includes spraying a high pressure fluid jet from a nozzle toward the hole and in a direction generally parallel to the central axis of the hole. The fluid jet is substantially free of solid particulate thereby permitting the jet to remove the bond coat and the thermal barrier coating from the hole without removing metal from the piece.

Abstract: In a pulse laser drilling process having a machine control for controlling a laser, an apparatus is provided to detect when a hole is drilled through a workpiece. The apparatus detects a laser pulse, where the laser pulse emits a laser light upon drilling impact with the workpiece. A second detection step detects sparks emitted by the workpiece, and a spark signal amplitude representative thereof is produced. The sparks produce visible wavelength light. A filter blocks the laser light and transmits the visible wavelength light. A photosensor associated with the filter senses when the spark signal amplitude diminishes below a predetermined threshold level. An output signal, responsive to the photosensor indicates when a through hole is complete and indicates to the machine control to stop any further laser pulse.

Abstract: A method for forming a slot in a metal component having first and second opposite surfaces utilizes a first laser beam having a pulse rate and power to vaporize the metal. The laser beam is traversed across the first surface at a feed rate so that each beam pulse vaporizes the component metal at a spot. The laser beam pulse rate and feed rate are effective so that successive spots do not substantially overlap each other. The laser beam is traversed in repeated steps in a series of passes so that the spots collectively form a continuous slot to a depth below the first surface. In a subsequent step, a second laser beam is positioned in the slot to drill a hole through a base of the slot, with the second laser beam being repositioned to drill a plurality of the through holes spaced apart from each other along the length of the slot.

Abstract: A method for forming an aperture in a component wall made of metal, the aperture having a diffuser which opens up and outward from a bottom of the diffuser to a first surface of the wall, the method includes the following steps: A) laser machining the wall with a laser which produces a laser beam having a pulse rate and power sufficient to vaporize the metal; B) firing and traversing the laser beam, preferably at an acute angle, across the surface to a predetermined first edge of the diffuser in a single pass starting at a centerline of the diffuser; and C) traversing the laser beam at an increasing rate of speed during the pass so that each beam pulse vaporizes the metal at a laser spot such that successive laser spots substantially overlap each other in decreasing amounts and the pulses nibble out the metal to form a continuous trench below the surface.