Hot Corrosion of Nickel alloys for aero-engine applications

Lead Research Organisation: Imperial College London
Department Name: Materials

Abstract

The project will help understand the fundamental effect of refractory elements on nickel superalloy corrosion. Nickel superalloys are used in the turbine blades and discs of aero-engines because of their outstanding mechanical properties up to elevated temperatures. Rolls-Royce plc, as a world leading aero-engine manufacturer, has a strong interest in understanding the failure mechanisms of alloys in service, in order to improve them. Some nickel-based superalloys fail substantially faster than others when exposed to sulphur-containing compounds, however, the mechanisms are not well understood. Refractory elements such as Mo, W, Re and Ru can accelerate the rate of corrosion when the alloy is exposed to corrosive gases and molten salts. A systematic study producing alloys with varying compositions that swap refractories (Mo/W) with elements that form protective oxides (Cr/Al) is required to understand the effect of those elements. Your project will involve the production of new alloys, advanced characterisation techniques such as scanning/transmission electron microscopy, atom probe tomography and synchrotron-based techniques. It will involve mechanical testing under different environments and some thermodynamic modelling to understand the failure mechanisms.

Publications

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