Grant: Research Tools and Instruments

Profs Daymond and Persaud seek to develop a mechanistic understanding of the combined effect of irradiation and corrosion on materials. To understand both the separate and synergetic effects of corrosion and irradiation it is critical to be able to quantify the local crystallography of the materials being studied. We are fortunate to be able to irradiate materials and handle them afterwards at the Queen's Reactor Materials Testing Laboratory (RMTL; www.rmtl.ca). This RTI will add an 'Electron Back Scatter Diffraction' (EBSD) detector to our Scanning Electron Microscope (SEM) at RMTL, enabling us to study crystallographic effects on degradation of irradiated materials, a unique capability at a university in Canada. How irradiation effects deformation, crack initiation and how it effects the interaction between stress and corrosive environment at the microscale is poorly understood. Real materials are made up of grains or crystallites - each individual crystallite is typically highly anisotropic in its response to stress. We study this local heterogeneity to understand how irreversible microstructural changes occur and propagate. To understand the impact of local microstructure on deformation, and to determine how irradiation and/or environment can further influence failure, we first need to be able to measure the microstructure. EBSD is the only lab-based tool capable of giving us spatial mapping grain orientations, by enabling electron diffraction as a function of position on a sample. Further, a relatively recent modification of the EBSD technique (High Resolution-EBSD) allows determination not just of grain orientation but of local stresses. This approach gives us direct insight into contributions of various local crystallographic conditions to deformation and failure. Acquiring this EBSD instrument will immediately advance our current state-of-the-art materials science and corrosion research programs. The ability to effectively study crystallographic effects on irradiated materials will significantly address the current gaps in mechanistic understanding of degradation in many nuclear materials. The latter includes understanding material behaviour for operating nuclear power plants, new designs and next generation reactors, as well as nuclear waste storage applications. This will help in our research to prolong the lifetime of existing nuclear plants to the benefit of Canadian electricity users, as well as helping in the design of new nuclear plants that will enable electrification and de-carbonisation of our society.  This represents a pressing societal need, requiring significant investment in new electricity generation capability as our transport networks and heavy industry move away from carbon-based power.  Base-load power provided by nuclear will be a significant component, along with intermittent renewables, in addressing Canada's future need for electricity.