The development of high temperature structural materials is a critical challenge to the implementation of nuclear fusion. We are testing advanced candidate structural materials up to 2000 °C in a graphite furnace testing rig. Deformed specimens are characterised by high resolution microscopy to understand failure mechanisms, such that in-service performance can be predicted with greater fidelity.
IRRADIATION DAMAGE RESISTANCE
Assessment of irradiation damage tolerance is critical to understanding a material's lifetime in service. Irradiations are carried out in national nuclear facilities and are evaluated by transmission electron microscopy, atom probe tomography, and small-scale testing methods such as nanoindentation.
OXIDATION STUDIES AND COATINGS
Oxidation resistance is a particular challenge in fusion reactors, where performance under a sudden loss of coolant and vacuum must be understood and mitigated against. Kinetic studies are carried out using thermogravimetric analysis. This is combined with X-ray diffraction and microscopy to understand degradation mechanisms and inform the design of oxidation resistant coatings processed by chemical vapour deposition.
Composites of tungsten carbide and metallic cobalt are widely employed in machine tools, however cobalt is toxic to workers. This project is developing alternative composites with non-toxic metals. We are also developing tungsten boride-based composites, which are more challenging to produce, but have improved neutron attenuation performance, which makes them of interest for nuclear fusion reactor development.