Authors:
Robin Bright
Harris L. Marcus
Institute of Materials Science and the Department of Chemical, Materials, and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269-3136

As the use of pulsed lasers in the manufacture of cooling holes in high-temperature gas-turbine engine components continues to increase, understanding the material behavior during laser-material interaction and the subsequent effects on hole quality becomes critical. In this study, atomic emission spectroscopy is used to monitor the optical characteristics of ejected material during percussion laser-drilling of Waspaloy over irradiance and pulse duration values in the ranges of 10–20 MW/cm² and 0.3–1.1 ms, respectively. While irradiance is a widely used target parameter, it was experimentally determined that pulse duration had a larger impact on both the calculated electron temperature of the ejected material as well as on the thickness of residual resolidified, or recast, layer of material on the inside walls of drilled holes.