Micromechanical Studies of Fatigue in Superalloys
In the (very) high cycle fatigue regime crack initiation and short fatigue crack growth dominate fatigue lives. We have developed novel ultrasonic methods for very rapid (~106 cycles in <1 min) fatigue testing of very small (~0.5 to 200 µm across) material volumes cut by either FIB or laser micro-machining. Focussing the testing down to a small region allows the progression of deformation to be followed in detail for which a range of characterisation methods will be used. Secondary electron imaging in SEM will allow a rapid assessment of slip feature development and crack formation, while electron channelling contrast imaging will allow assessment of local dislocation structures. AFM will be used to quantify slip step heights and surface roughening which will be related to the underlying crystallography revealled by EBSD which also map intra-granular distributions of local stress and dislocation density.
The funded project is in collaboration with Rolls Royce and our interest is in developing underpinning mechanistic understanding of the effects of surface condition, coatings, surface finish, temperature and environment on fatigue in superalloys.
This project would suit a graduate with a background in materials science, metallurgy or mechanical engineering with a strong interest in advanced aerospace materials.
Individual applications will be considered as and when they are received and this position will be filled as soon as possible.
Any questions concerning the project can be addressed to Professor Angus Wilkinson ([Email Address Removed]). General enquiries on how to apply can be made by e‑mail to [Email Address Removed]. You must complete the standard Oxford University Application for Graduate Studies. Further information and an electronic copy of the application form can be found at http://www.ox.ac.uk/admissions/postgraduate_courses/apply/index.html.
This 3.5 year DPhil in Materials studentship is jointly funded by the Department’s EPSRC DTP grant and Rolls Royce. It will provide full fees and maintenance for a student with home fee status (this status includes an EU student who has spent the previous three years in the UK undertaking undergraduate study). Candidates with EU fee status are eligible for a fees-only award, but would have to provide funding for their living costs from another source such as personal funds or a scholarship. The stipend will be approximately £15,777 per year. Information on fee status can be found at http://www.ox.ac.uk/admissions/graduate/fees-and-funding/fees-and-other-charges.