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Professor of Metallurgy

MEng Imperial College London
PhD Imperial College London

Aerospace Materials

My research within the Rolls-Royce University Technology Centre is primarily focussed on developing materials and technologies to improve efficiency within the aerospace industry.  The European Commission has set out ambitious targets requiring the aircraft of 2050 to produce 75%; less CO2 and 65% less noise than those of 2000.  Achieving these targets requires the development of new, high temperature materials, capable of operating in more aggressive environments, and the incorporation of components capable of optimising engine performance across the entire flight cycle.

High Temperature Materials

Gas turbine engines follow the Carnot cycle and, as such, become more efficient when operated at higher temperatures.  Therefore, the next generation of aerospace engines will have to operate at higher temperatures and faster rotational speeds if they are to meet the emission targets mentioned above.  These increasingly hostile conditions are beyond the capability of currently available materials, and thus my research is focused on developing new solutions, both in conventional Ni-based superalloys and in alternative novel systems such as metallic-intermetallic alloys and the so-called “High Entropy Alloys”.

Micromechanics and Functional Fatigue of Transforming Alloys

Transforming materials, such as shape memory alloys, have the potential to revolutionise traditional engineering concepts by introducing components that are functional as well as structural and that can respond autonomously to their operating conditions.  Within a gas turbine engine, these materials will provide adaptive behaviour that will maximise efficiency during all segments of a flight cycle.  However, widespread uptake of these materials has been limited as their properties often deteriorate with repeated cycling, commonly referred to as functional fatigue.  My work in this area is aimed at developing a fundamental understanding of the micromechanics of these materials whilst they transform, requiring the use of in situ techniques such as high-energy synchrotron diffraction.

Themomechanical Processing of Engineering Alloys

The majority of engineering components used today are thermomechanically processed during their manufacture.  These processes are not only part of the forming operation but in many cases are necessary to achieve the correct microstructure and mechanical properties required in service.  Therefore, understanding the deformation behaviour of materials during processing is critical to establish accurate descriptions of the mechanisms that control microstructural evolution.  My research covers a range of engineering alloys, developing mechanistic understanding from microstructural and process data.

In situ synchrotron diffraction spectra showing the two stage phase transformation in a NiTiCu shape memory alloy during heating and cooling under an applied load.
  • N. G. Jones, K. A. Christofidou, P. M. Mignanelli, J. P. Minshull, M. C. Hardy and H. J. Stone: The influence of elevated Co and Ti levels on a polycrystalline powder processed Ni-base superalloy, Materials Science and Technology 30(2014) 1853
  • N. G. Jones, J. W. Aveson, A. Bhowmik, B. D. Conduit and H. J. Stone: On the entropic stabilisation of an Al0.5CrFeCoNiCu high entropy alloy, Intermetallics 54 (2014) 148
  • N. G. Jones and D. Dye: Martensite evolution in a NiTi shape memory alloy when thermal cycling under and applied load, Intermetallics 19 (2011) 1348
  • N. G. Jones, R. J. Dashwood, M. Jackson and D. Dye:  Beta phase decomposition in Ti-5Al-5Mo-5V-3Cr, Acta Materialia 57 (2009) 3830
  • N. G. Jones, R. J. Dashwood, D. Dye and M. Jackson: Thermomechanical Processing of Ti-5Al-5Mo-5V-3Cr, Materials Science and Engineering A470 (2008) 369