Methods of employing lasers in the production and repair of cooling holes used in the latest turbine engine designs

The latest Turbine Cooling Hole designs employ strategies that maximize engine efficiency in ways that were unheard of just a few years ago. These include randomly spaced and angled cooling holes, that often include “fan-shaped” exits to provide efficient, diffused cooling, and Thermal Barrier Coating (TBC) of the component’s surfaces. The challenges that are presented in manufacturing these cooling holes are discussed and the techniques used to make parts are explained. Laser is an ideal method of working with these new requirements; pulsed Nd-YAG, CO2 and Q-switched Laser solutions are described. Repair and Overhaul techniques are particularly difficult as used engine parts are seldom in the original form to when first produced, having been distorted under the stresses of high-temperature service. The ability to compensate for these variances are discussed, using specifically-derived algorithms employing various contact and non-contact probing methodologies.