Understanding intermediate temperature fatigue crack growth in single crystal Ni-based superalloys

Rolls Royce are sponsoring an Industrial CASE award for four years, working on fundamental fatigue failure investigations in a range of aeroengine turbine blade systems. Understanding what controls the fatigue processes, cracking rates and the crack paths taken in turbine blades is extremely important in both future blade design, but also in informing current inspection and repair approaches. These turbine blade materials typically experience a range of service temperatures, loads and environmental conditions in the aeroengine. The interplay of these testing parameters in the single crystal nickel base superalloy turbine blade components offers a fascinating set of complex service failures that need detailed investigation and explanation. The PhD will focus on understanding how these complex cracking processes occur, and what controls these processes. Advanced mechanical testing capabilities in our testing structures research laboratory (TSRL) will be used to conduct high temperature mixed mode loading fatigue tests in a range of testing environments. Post-test fractographic analysis will include scanning electron microscopy and the use of X-ray CT to evaluate crack tip processes in 3D in our state-of-the-art X-ray tomography centre (mVIS) which is also part of the National Research Facility in X-ray imaging.