Decoupling Hardening mechanisms in irradiated materials (materials strand project)

Supervisor/s – David Armstrong and Angus Wilkinson (University of Oxford). Chris Hardie (UKAEA).

Future nuclear power systems, both fission and fusion, rely on the development of materials which can withstand some of the most extreme engineering environments. These include temperatures up to 1500oC, high fluxes of high energy neutrons and effects of gaseous elements produced by transmutation and implantation from the plasmas. Due to efforts to minimise the production of nuclear waste by such reactors the range of elements which may be used in structural components is limited. In many cases there is a lack of understanding of the basic deformation processes that occur in either pure materials or alloys and importantly how these are affected by temperature, radiation damage and gas content.

During the irradiation process a wide range of defects can be produced including point defects, dislocation loops, voids and precipitates. These all contribute to the hardening of irradiated materials by a complex relationship between themselves and pre-existing grain boundaries, dislocations and alloying features. Decoupling the effect of one defect type from another is extremely challenging and hampers the ability to computationally model deformation of irradiated materials.

By working with specially prepared alloys with controlled compositions and specific irradiation conditions this project aims to decouple the different hardening mechanisms and provide information for improved materials models incorporating irradiation hardening.

The methods to be used will be arc melting and associated thermomechanical treatments for production of the model alloys. Irradiation damage will be performed through the UKNIBC and NNUF facilities. Mechanical testing will be performed using a range of nanoindentation equipment at Oxford and CCFE-MRF. Characterisation of the defect-dislocation interactions will be carried out TEM and SEM methods.

This project is offered by The University of Oxford. For further information please contact: David.armstrong@materials.ox.ac.uk

This project is not compatible with part time study.