A funded 3-year UK/EU PhD studentship is available in the group of Dr Sandy Knowles within the School of Metallurgy and Materials at the University of Birmingham, with a stipend of £14,777 per year.
This project will link to Rolls-Royce and TIMET as industrial partners.
The research group investigates new alloys for extreme environments in aerospace gas turbines as well as nuclear fusion/fission reactors. This involves the design of new alloys; production through arc melting, powder metallurgy or additive manufacturing; characterisation using electron microscopy and x-ray diffraction; mechanical testing using macro/micro-mechanical methods and failure investigation.
The fuel efficiency of aerospace gas turbines is strongly linked to their operating temperature. However, increasing the operating temperature puts increased demand on the materials employed, namely nickel-based superalloys. Over 50 years of this development nickel-based superalloys have become highly sophisticated, but further improvements are increasing hard to realise  and are approaching a capability ceiling.
One possibility for increased high temperature capability is to change the base element to one with a higher melting point than Ni (Tm=1455°C), for example Mo (Tm=2623°C) or Nb (Tm=2469°C). However, this results in a change in the matrix crystal structure from γ face-centred-cubic (fcc) to β body-centred-cubic (bcc) necessitating a change away from the γ’ Ni3Al precipitates used for Ni. A larger number of ordered-bcc β’ intermetallics exist but few exist in equilibrium with Mo or Nb, and typically include rare or expensive elements, e.g. Pt or Ru , or rely on a matrix of Cr (Tm=1907°C)  or Fe (Tm=1538°C) . Recent work has demonstrated for β Ti (Tm=1668°C) alloys that β’ TiFe can be used as a reinforcing precipitate and that this has compatibility with β Mo and Nb .
Whilst recently demonstrated as being possible, the capability of Mo or Nb based ‘bcc superalloys’ with the β matrix reinforced by β’ TiFe intermetallic precipitates remains unknown. Further work is needed to commercialise the concept. In particular, the compatibility for oxide scale former elements Si, Al, Cr to promote oxidation resistance remains undemonstrated. This project would produce new Mo and Nb ‘bcc superalloys’, characterise their microstructures, evaluate their oxidation and mechanical properties as well as their underlying deformation mechanisms.
The candidate will have a 1st class Undergraduate or Masters degree (or equivalent) in Materials Science, Mechanical Engineering, Physics or related discipline. A background in microstructural characterisation and/or mechanical testing would be advantageous.
Applications should be made through the university’s online application system: https://www.birmingham.ac.uk/postgraduate/courses/research/metallurgy-materials/metallurgy-materials.aspx?OpenSection=HowT
Please provide a cover letter summarising your research interests and suitability for the position, the contact details of two referees and a curriculum vitae. Please send a copy directly to Sandy Knowles.
Any question please contact Sandy Knowles: [email protected] http://www.birmingham.ac.uk/staff/profiles/metallurgy/knowles-alexander.aspx