Product Code: ICAL07_1202

Laser Design Characteristics and Parameter Variables and Their Impact on Percussion Hole Quality
Authors:
Robert Wright, University of Hartford; West Hartford CT USA
Terri Marsico, Conneticut Center for Advance Technology; East Hartford CT USA
Paul Denney, Conneticut Center for Advance Technology; East Hartford CT USA
Presented at ICALEO 2007

Laser drilling is the primary method for the production of cooling holes in gas turbine engine components. Hole quality, which includes surface debris (its amount and location), hole taper, size, and barreling, is a major factor in determining the success of the cooling holes and therefore the performance of the engine. As the number of holes and their complexity (depth, incidence angle, and location to internal features) increase, consistency in hole quality is paramount. Past quality levels have been acceptable for previous engine designs but the more advanced designs require higher standards. This paper examines characteristics related to the design of the laser used (single or two rod designs) and laser parameters on a wide range of quality metrics. The authors examined laser beam characteristics as pulse-to-pulse stability and pulse power variations through out the pulse and how these factor into hole quality. The paper also examines how the fluence impacts hole dimensional characteristics and the location and amount of debris.