Aero engine components – optimised validation techniques
When an inspected part is validated, its production process is 'frozen'. Subsequent modifications that are required due to small changes in machinery over time incur time-consuming and costly revalidation. The EU has funded the project 'Adaptive control of manufacturing processes for a new generation of jet engine components' (ACCENT) to address this. The project comprises of a large European consortium that will work on instilling safe flexibility in the manufacturing and validation pipeline. Scientists are developing standards for the validation of safety-critical components manufactured within a process parameter window rather than strictly defined process parameters. This process parameter window is maintained through adaptive control via process monitoring technology. With its innovations, ACCENT expects to save the industry recurring validation costs while optimising design and manufacture. Partners successfully demonstrated the ACCENT concept using an expanded process parameter window and adaptive process control to machine the alloy (Inconel 718). Complex-shaped slots in turbine discs (broaching) were manufactured. Along the way, project-related research supported nine doctoral dissertations and nine master’s theses, and led to 25 publications in European and international journals and conferences. Furthermore, excellent cooperation resulted in a complete list of surface features and anomalies, as well as guidelines on methodologies for surface integrity examinations. ACCENT brought together leading European aero-engine manufacturers and university research groups to enhance the competitiveness of safety-critical component production. Advances in process monitoring and control enabled a demonstrated decrease in manufacturing costs with a simultaneous increase in component quality. Partners and end users are currently benefiting from implementation, and cooperation with the European Aviation Safety Agency (EASA) could facilitate standardisation in the future.
