David Armstrong

My research group work on understanding the behaviour of materials under extreme environments, such as radiation damage, high temperatures or high stresses. By developing an understanding of the mechanical behaviour and defects which control materials behaviour we then try and develop materials better able to operate under extreme conditions. We are now working to take technqiues we have developed for traditional engineering materials and apply them to questions in other areas such as solid state batteries for energy storage and geological materials.

Much of our work is centred on developing mechanical testing techniques at the nano and micro scale. We acces to in-situ and ex-situ high temperature nanoindentation systems which allows us to perform tests up to temperatures above 1200K. These techniques are being used to study a range of important materials for both nuclear power and aerospace applications. We also work with leading groups in Oxford and elsewhere to use understanding gained from our experiments to process new materials better suited to working under extreme conditions.

Materials systems being studied include; ceramic composites, high entropy alloys, refractory alloys, high strength steels and zirconium alloys. This is carried out with a range of partners including, within the UK, UKAEA, Tokamak Energy, Rolls Royce, and The European Space Agency, and intenationally EPRI, UC Berkeley, and University of Wisconsin-Maddison, USA, as well as many collaborators within Oxford. Particular areas of current research include:

• Materials for nuclear fission and fusion
• Mechanical behviour of materials for energy storage
• Development of micromechanical testing techniques
• High entropy and nanostructured alloy development
• High temperature mechanical properties
• Time dependent deformation
• Ceramic composite materials for energy and aerospace
• Deformation in geological materials