Ponente
Descripción
The IFMIF-DONES facility will be dedicated to irradiating structural materials intended for the usage in future fusion reactors. However, this unique facility has the potential to support additional complementary experiments beyond its primary purpose, thereby broadening its utility to other research communities where neutrons can be applied. Neutrons are extensively used in neutron radiography and computed tomography across various scientific fields, including life sciences, geology, archaeology, material science, and non-destructive testing of industrial components.
Neutron Computed Tomography (NCT) is a non-destructive imaging technique that utilizes neutrons to generate detailed 3D images of an object's internal structure. Unlike X-rays, neutrons interact weakly with most metals but strongly with hydrogen and other light elements, making them especially useful for studying materials that contain light elements or are embedded within dense metal matrices. The process begins with neutrons generated from a nuclear reactor or spallation source. The sample is then placed between the neutron source and a detector, where neutrons pass through and interact with the material. These interactions are recorded, and the captured data is reconstructed using CT algorithms to produce a 3D representation of the monitored object bulk structure.
In-situ testing involves studying materials under realistic operational conditions such as varying temperatures, mechanical loads, or chemical environments. This approach allows researchers to observe the real-time behavior and evolution of materials, providing valuable insights into their performance and failure mechanisms. When combined with NCT, in-situ testing can reveal changes in internal structures and defects under different conditions, offering a deeper understanding of how materials response under subjected loadings.
Digital Volume Correlation (DVC) is a computational technique used to analyze 3D images, such as those obtained from NCT. DVC tracks the full-field (i.e., displacement and deformation) of features within the material by comparing grayscale intensity patterns in sequential volumetric images. The process involves acquiring a series of 3D images at different stages of deformation or loading, dividing the images into small subsets/elements, and tracking their kinematics through correlation analysis. The displacement field is then measured, showing how each point (i.e., voxel) within the material has moved. From this data, strain fields can be derived, providing insights into the material bulk strain distribution.
This combined methodology is particularly valuable in fields such as materials science, where it is used to study the deformation, fracture, and fatigue behavior of advanced materials, including composites and metals. In geosciences, it aids in investigating the internal structures and stress distribution in geological samples under pressure. In biology and medicine, it allows for the examination of the internal structures of biological tissues and medical implants. Additionally, in engineering, this approach is crucial for assessing the performance and failure mechanisms of components and structures under operational conditions.
NCT, in-situ testing, and DVC together provide a comprehensive toolkit for investigating the bulk behavior of materials in real-time and under realistic conditions. This integrated approach enhances the understanding of material properties, leading to improved material design, performance assessment, and failure prediction in various applications.
Acknowledgments
The Croatian Science Foundation HRZZ-UIP-2019-04-5460 (FULLINSPECT) support is gratefully acknowledged.
