Abstract: The present invention provides a method of laser machining a cooling hole in a hollow gas turbine component, the cooling hole including a circular cross section metering hole and a diffuser with an opening which extends from a shape locus in the metering hole to a trapezoidal cross section opening by firing a series of laser pulses at an acute angle at the outer surface of the component toward the shape locus to create the diffuser opening, with the laser pulses penetrating the component outer surface up to but not substantially beyond the shape locus, then firing the laser through the shape locus and the inner surface of the component to create the metering hole having a circular cross section. Alternatively, the initial laser pulses are fired to create the central portion of the diffuser opening, then firing the laser to create the metering hole, followed by firing the laser along the peripheral portion of the diffuser opening.

Abstract: A process is provided for laser drilling to remove coating material obstructing cooling holes of a gas turbine component by utilizing a CNC component program which is preprogrammed with the general location of the cooling holes of a component to move a machine vision system and component relative to each other to each cooling hole location for a series of cooling holes, determining the actual location for each cooling hole and storing in the memory of the CNC or a data storage device the actual locations for the cooling holes for the series of cooling holes, followed by laser drilling based on the actual location of the cooling holes stored in the memory of the CNC or the data storage device to remove the coating material obstructing the cooling holes for the series of cooling holes. This process can be advantageously carried out to determine the actual location of the cooling holes either on a coated component or a component that has been prepared for coating.

Abstract: A process is provided for laser drilling relatively large and deep holes in superalloy components by percussion laser drilling a central hole through the component to a diameter less than the predetermined diameter, then trepanning laser drilling around the central hole to expand the diameter of the hole to the predetermined diameter. The steps are repeated to deepen the hole.