Taking Co/Ni superalloys into service
Professor David Dye
Imperial College London
New Co/Ni alloys the research team have recently patented show great promise for polycrystalline applications where traditional P/M 50% 𝛾′ Ni superalloys cannot be fabricated, e.g. where isothermal forgingroutes are impractical. Examples include thin section applications, where the low solvus temperatures alloy hot rolling, die forging and induction forging process routes, where dynamic recrystallisation allows very fine grain sizes (with improved strength and fatigue performance) to be achieved [eg Nicolaÿ et al., Acta Mater, 2019].
(1) The primary technique will be EBSD characterisation and segmentation of deformed vs dynamically recrystallised grains, and the associated texture and grain-average misorientation analysis.
(2) Mechanical characterisation via rolling and forging simulation in the Gleeble.
(3) SEM characterisation of the 𝛾′ and grain boundary phase microstructures, their evolution and effect on the microstructure evolution during forming.
(4) TKD and (S)TEM measurements using NBED-type modes to quantify the grain boundary and nanoscale oxide phases developed. There is the potential to complement these with APT analysis if required.
|Note||Applicants for this project may be required to be eligible for security clearance to work on UK government programmes|
For information on how to apply for this project please visit cdt-acm.org/phd-opportunities
Being part of the CDT-ACM was an all-round fantastic experience; I not only received great training in a range of advanced characterisation techniques, but I also made strong links with industry and strong bonds with my cohort which have both led to fruitful collaborations.