Dwell fatigue crack growth in next generation RR1073 nickel disc alloys

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Within this project microstructural factors which affect the behaviour of dwell fatigue crack growth will be investigated. It will employ advanced material characterisation techniques such as analytical-Transmission Electron Microscopy (TEM) to understand effects of underlying microstructure. In the aerospace industry there is great demand for nickel-based superalloys which can withstand the increasingly higher temperatures found within gas turbines. Allowing turbines to operate at higher temperatures is beneficial in terms of their thermodynamic efficiency and fuel consumption. However, these materials must be manufactured to be able to withstand creep deformation, oxidation and other environmental processes beyond current limitations.RR1073, requires rigorous mechanical testing to determine its viability at temperature. One central research interest lies in observing dwell fatigue crack growth for this new nickel-based superalloy, which will be used for rotor disc applications in an aero-engine gas turbine. Dwell fatigue occurs in the superalloys due to the cyclic loading experienced during aspects of an aircraft's flight and especially during take-off. Therefore, it is important to understand how to optimise dwell crack growth resistance through controlling microstructures and most importantly by controlling the distributions of gamma prime precipitates. The programme will involve detailed investigation of the effects of ageing temperatures and cooling rates on the development of such distributions.