The Repair of Single Crystal Nickel Superalloy Turbine Blades Using Laser Engineered Net Shape (LENS) Technology

Abstract : A feasibility study to evaluate Laser Engineered Net Shape (LENS(TM)) technology as a general repair vehicle for single-crystal nickel superalloy turbine blades was conducted. A variety of deposition conditions at several locations were examined. The crystallographic orientation and microstructures of the deposits and substrates were examined using a scanning electron microscope (SEM) equipped to collect Electron-Back-Scatter-Diffraction (EBSD) data. The results of this study indicated that, for a variety of deposition conditions, it was possible to produce deposits that had the same crystallographic orientation as the substrate. The main difficulties encountered were the development of cracks in the deposits and the unreliability of the LENS(TM )system used.