Implementation of an automated, adaptive grinding solution will reduce production labor costs and improve quality and performance. P&W images
The IPT, comprised of the Joint Program Office, P&W, Alcoa Howmet, and NMC, will develop and demonstrate an automated system to establish the required turbine airfoil trailing edge profiles.
An NMC-led Integrated Project Team (IPT) is focusing on the F135 engine turbine airfoil trailing edges, which are typically manually ground to obtain the desired contour. The current process results in high labor costs, as well as deviations in the profile that cause both yield and quality concerns. Previous development efforts by Pratt & Whitney (P&W) have demonstrated the capability of a force- and vision-adaptive robotic system to profile grind the blade trailing edges; however, other adaptive grinding processes are potentially viable. The cast-in cooling air discharge holes on the trailing edge pose another challenge, as technologies to identify holes and inspect airfoil edges exist but have not been integrated with adaptive-control methodology.
NMC and industry will generate conceptual designs that will integrate metrology, adaptive grinding, and robotics technologies. Several solutions will be down-selected for development and assessment. From those, P&W and Alcoa Howmet will determine the preferred automated airfoil grinding solution.
The project will reduce acquisition costs by an estimated $11,000 per engine set based solely on reduced scrap; additional labor savings will be quantified on the project during evaluation/validation of the preferred adaptive grinding solution. This equates to a five-year savings of $13M (1,188 engine sets). Additional savings from improved engine performance, reduced fuel burn, and repair are also expected. Further benefits may include supporting repair processes and strengthening the industrial base for commercial engines.
NMC will lead the development of the final specification for the full-scale system, as well as the corresponding tooling/fixturing drawings. P&W and Howmet will implement the chosen automated, adaptive grinding solution at Howmet in FY2019.
Joint Strike Fighter Program Office
Pratt & Whitney