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Rolls-Royce UTC

Department of Materials Science and Metallurgy

Studying at Cambridge

 

Katerina A. Christofidou

Katerina A.  Christofidou

Research Associate


Office Phone: +44 (0)1223 331950

Biography:

MEng Aerospace Materials Engineering (Imperial College London)
PhD Metallurgy (University of Cambridge)

Research Interests

Nickel and nickel-cobalt based superalloys and their development

Environmental issues are increasingly becoming a principal matter in the design of novel gas turbine civil aero engines. Fuel efficiency as well as  the need to reduce emissions necessitate that new engine designs implement increased gas stream temperatures and rotation speeds. However, current materials are incapable of withstanding the demanding environments. New materials, are therefore required in order to ensure the success of the novel engine designs. 

One of the strategies explored by our group is the modification of conventional Ni-based superalloys with increased Co and Ti contents, which when carefully controlled can provide improved properties to higher temperatures. 

Alloy design is a demanding task that involves the use of various techniques in order to tailor compositions through all stages of development. Thermodynamic modelling is used at the initial stages of alloy design. This is followed by the manufacture of specimens and their subsequent characterisation through thermal analysis, microscopy, advanced neutron and synchrotron diffraction techniques, mechanical testing and oxidation testing in order to analyse the suitability of the alloys produced. 

 

Multi-component alloys

"High Entropy Alloys" have proven to be an emerging area of research for modern metallurgy, from both a fundamentally scientific point of view and, for the more application-driven, a potentially interesting and promising set of new alloy systems. A range of characterisation techniques are used to understand the microstructure of these alloys focusing primarily on SEM-based techniques. 

 

Additive Manufacturing of Ni-based superalloys

One of the methods being explored for the manufacturing of high precision parts for gas turbines involves additive manufacturing of Ni-based superalloys. However, due to the complexity of the techniques themselves, and the specificity of the material properties required, the microstructure of parts produced by these methods needs to be extensively studied and modified before such parts can be put into service. My research focuses on the characterisation of such parts using a range of microscopy and diffraction techniques. 

Keywords

  • environmental degradation
  • characterisation
  • alloy design
  • diffraction
  • Ni-Co alloys
  • nickel-based superalloys
  • thermodynamics
  • turbine discs
  • novel alloy development
  • DSC/TGA
  • microstructure
  • thermo calc
  • DSC
  • alloy development

Key Publications

1. K.A. Christofidou, N.G. Jones, E.J. Pickering, R. Flacau, M.C. Hardy, H.J. Stone, The microstructure and hardness of Ni-Co-Al-Ti-Cr quinary alloys, Journal of Alloys and Compounds. 688 (2016) 542–552. doi:10.1016/j.jallcom.2016.07.159.

2. K.A. Christofidou, N.G. Jones, M.C. Hardy, H.J. Stone, The Oxidation Behaviour of Alloys Based on the Ni–Co–Al–Ti–Cr System, Oxid Met. 85 (2015) 443–458. doi:10.1007/s11085-015-9606-8.

3. N. G. Jones, K. A. Christofidou, P. M. Mignanelli, J. P. Minshull, M. C. Hardy, H.  J. Stone, Influence of elevated Co and Ti levels on polycrystalline powder processed Ni-base superalloy, Materials Science and Technology 30 (2014) 1853

 

Other Publications

1. N. G. Jones, K. A. Christofidou, and H. J. Stone, Rapid precipitation in an Al0·5 CrFeCoNiCu high entropy alloy, Mater. Sci. Technol., vol. 31, no. 10, p. 1171-1177, 2015.

2. N.G. Jones, R. Izzo, P.M. Mignanelli, K.A. Christofidou, H.J. Stone, Phase evolution in an Al0.5 CrFeCoNiCu High Entropy Alloy, Intermetallics 71 (2016) 43–50. doi:10.1016/j.intermet.2015.12.001.

3. http://www.cins.ca/docs/exp_rep/CNBC-2015-SD-5.pdf

4. http://www.cins.ca/docs/exp_rep/CNBC-2015-SD-11.pdf

RSS Feed Latest news

Dr. Lewis Owen appointed to a Junior Research Fellowship at Gonville & Caius College Cambridge

Jan 24, 2018

Dr. Lewis Owen has been appointed to a Junior Research Fellowship commencing in October 2018 at Gonville & Caius College Cambridge. We look forward to many more years of high quality research into the wonderful world of short range order.

Cambridge Academy for Science and Technology Visit

Jan 17, 2018

We had a fantastic time today hosting the uber-talented students from the Cambridge Academy for Science and Technology. We believe sharing some of our research and encouraging as many people as possible to consider STEM careers is a key responsibility for any scientist/engineer.

PhD studentships now available within the group

Jan 09, 2018

Navigate onto our vacancies page to find out more!

Strategic Partnership with Rolls-Royce shortlisted for a Times Higher Education Award 2017

Oct 03, 2017

The Rolls-Royce partnership with the universities of Cambridge, Swansea and Birmingham has been shortlisted for a Times Higher Education Award 2017. Find out more here: https://www.timeshighereducation.com/news/times-higher-education-awards-2017-shortlist-announced

New high temperature thermocouple

Nov 14, 2016

Dr. Michele Scervini has developed a new thermocouple for high-temperature applications