James Marrow

My research is focussed on the degradation of structural materials and the role of microstructure, generally by the investigation of fundamental mechanisms of damage accumulation using novel materials characterisation techniques. This often employs numerical analysis of images (e.g. 3D images by computed X-ray tomography) with strain mapping by digital image correlation, together with crystal strain measurements by synchrotron X-ray and neutron diffraction. At higher resolution, we also use analysis of images obtained by electron microscopy together with strain mapping by electron backscatter diffraction. We apply these methods to study the degradation of materials such as graphite and silicon carbide composites for Generation IV nuclear energy, as well as new materials for electrical energy storage. Nuclear energy is an important topic, as the next generation of nuclear power systems must be demonstrably safer, proliferation resistant and efficient. They will not provide power for some decades to come. Their development requires new high temperature fuels and structural materials with resistance to irradiation. This can only be achieved through fundamental understanding of materials microstructure and the mechanisms of materials ageing that affect their mechanical properties. Research in engineering materials for energy generation is not a quick-fix topic. New materials take from 15-20 years to come into service, and then are expected to be in service for 40-80 years. The key physical mechanisms that determine manufactured performance, and how these properties age in service, are not very well understood, and mistakes in materials selection can have enormous financial and social implications. Prediction is a major challenge, and deep understanding of the fundamental mechanisms of materials aging is essential to identify and avoid potential "cliff-edges" in future materials performance.