Objectives and content
This project is the result of a concerted European aero-engine industry effort; it also includes a partner representing an end user of aero-engines as well as a developer of surface treatment processes and a research organisation specialising in testing and understanding material behaviour.
This 48 month programme will provide a methodology for specifying the optimum surface condition for fatigue sensitive components operating in aero-engines and thus lead to lower life cycle costs for the engine, increased reliability and improved safety. It will contribute to a better competitive position for the European aero-engine industry.
Gas turbine engines require materials to be operated at the limits of stress and temperature to achieve a competitive engine performance. Rotating components, such as discs, are critical to the safety of the aircraft as failure leads to uncontained fragments with high kinetic energy and elevated temperature which can impact and hazard the airframe and controls. The vast majority of fatigue failures are surface originated, a combination of both the material and the surface condition. While new high strength "clean" materials, developed for such parts, do give better basic material fatigue performance as well as increased temperature capability, in order to realise these advantages it is essential to achieve the optimum surface condition of these critical components. An optimum surface condition must be tolerant of surface damage such as scratches and dents received during handling as well as offering a sufficient advantage in the undamaged state.
The main objectives of this proposal are:
- A comprehensive database of specimen results showing the performance of both current and near term future surface conditions on both a nickel and a titanium alloy in the undamaged and the damaged state.
- A fully validated methodology to identify an optimum surface condition for a given application, both in terms of selecting the best current condition and specifying the parameters for process developers to achieve in future surface conditions.
- A standard method for introducing artificial damage into components that is suitably representative of damage introduced in practice.
Rolls-Royce, an industrial partner, will lead this proposal and have defined the programme. Other engine manufacturers, i.e. MTU, SNECMA, Turbomeca and BMW-RR, all industrial partners, will take roughly equal shares of the technical work in terms of testing both specimens and discs, as well as correlation and method development. Inasmet, a Research Organisation partner, will perform specimen testing and analysis of the results. The DRA, representing a user of gas turbine engines and a Research Organisation partner, will test both specimens and discs in recognition of the importance of making rational decisions over service arisings in damaged critical parts. Finally Cranfield University, a Higher Education partner, will develop an existing coating process for improved fatigue behaviour. The other new surface condition under consideration, ultrasonic peening, can be arranged by subcontract.
Funding SchemeCSC - Cost-sharing contracts
MK43 0AL Cranfield,bedford
GU14 0LX Farnborough - Hampshire
20009 San Sebastián