Features at the microstructural scale – dislocations, point-defects, precipitates, grain boundaries, and their synergistic interactions – control materials’ mechanical properties. Radiation damage in materials introduces a variety of defects at this scale: point defect clusters, solute segregation, dislocation loops, voids and bubbles. The interactions of the “normal” microstructure, and modifications arising from radiation damage, with cracks and dislocations determine the usability and the lifetime of materials in structural nuclear applications.
This project is focused on materials for next-generation nuclear power plants. It will develop an innovative multi-faceted experimental programme operating at and adjacent to the microstructural length scale, linked to modelling at the same length scale. The project will build on and combine the strengths of existing research teams, and will involve close collaborations between the academic partners and research institutes and industry in the UK, Europe, Japan and the USA. A key strategic aim is to contribute to maintaining a leading position for the UK.
The project will be based on innovative techniques for Micromechanical testing of FIB-machined specimens a few microns in size. This will allow us to study a wide range of tightly-specified irradiation effects on mechanical behaviour of materials rapidly and cheaply, compared to the use of reactor irradiations and hot-cell tests. To test materials over the temperature range relevant to reactor operation will require development of a unique AFM / nanoprobe, operating up to 700°C in a controlled environment.
Mechanical experiments will be closely integrated with electron and atom-probe microscopy of the radiation effects (including effects of H and He); post-irradiation TEM and in-situ TEM irradiations, in-situ TEM deformation, and TEM of deformation structures from micromechanical experiments to study the details of hardening mechanisms. Analytical TEM and atom-probe microanalysis will be used to study clustering, phase separation and diffusion profiles at grain boundaries in irradiated and heat-treated material, evolution of ODS particles during heat-treatment of mechanically alloyed materials and behaviour of H and He at ODS particles and grain boundaries.