Extending Gas Turbine Engine Blade Life Saves Millions

Applications

• Military and Commercial Significance:
• AFRL and its partner, LSPT, designed and built an advanced laser system, the RapidCoater, to extend gas turbine engine blade life, thereby enhancing productivity and lowering costs. The RapidCoater system is a major innovation to the LaserPeen™ system and laser peening technology. It increases the process throughput by six to nine times, improves the reliability and repeatability of the process, and lowers the cost of processing by about 40%. The RapidCoater system is the ultimate automated method for applying the overlay coatings spot by spot at high speed. Essentially, it consists of a specialized airbrush spray nozzle, which is computer controlled to apply and remove the overlays at the specified times while a part is processed.
• Currently, General Electric Aircraft Engines (GEAE) has three operational RapidCoater production machines and is collaborating with the AF on an application for the F101, as well as the F110, gas turbine engine used in the F-16 Fighting Falcon. To date, GEAE has treated more than 20,000 F101 blades and transitioned the technology for application on the F110 engine, treating more than 2,000 blades. GEAE is working to apply the proven LSP technology to other engine components and commercial product lines in a cost-effective manner.
• AFRL sponsored several efforts to demonstrate the diversity of LSP and the RapidCoater. General Research Corporation International, of Vienna, Virginia, experimentally demonstrated superior foreign object damage tolerance capability for LSP as compared with mechanical shot peening. LSPT successfully modeled elastic shock wave propagation and corresponding material effects of the LSP process on titanium alloys. The University of Dayton Research Institute used finite element analysis techniques to predict residual stresses induced by LSP. These successful efforts facilitated development of new applications for LSP.
• LSPT and Pratt & Whitney are also expanding LSP applications to integrally bladed rotors and large components, initially for application in the F119 engine of the F-22 Raptor. This avoided a potential redesign and retrofit that would have cost as much as $10 million.