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Fig. 77: Schematic showing typical examples of the evolution of cavity shape for the evolution type. a) Type 1A, (b) Type 1B, (c) Type 2, (d) Type 3 and (e) Type 4, along with assigned symbols, accompanied by a corresponding plot showing evolution of lengths of bounding box with strain. Orientation of the edges of the bounding box is on the basis of the coordinate system shown in top right corner of inset in (a).
Fig. 76: 3D rendered volumes showing evolution of (a) cavity number 9 and (b) cavity number 26 with strain, (marked at the bottom of each box) in the sample. The type of evolution has been marked using symbols in the top left corner (see Figure 77 for reference). A different view of the cavity at the last scan has been also shown (highlighted by a box), for better comprehension of the 3D shape of the cavity (cavities are in red and intermetallics in green).
damage or cavities in real time, with a pixel size of 100 nm and a scan time of 7 seconds. To perform such imaging, it is crucial to have a high-flux X-ray source like that available at ID16B in order to ensure fast imaging so that the dynamics or changes can be captured.
The sample showed the presence of several pre-existing cavities in its initial state (with an average equivalent radius of less than 1 μm). The evolution of 30 of these cavities was tracked during deformation and it was observed that the cavities followed intricate and unique growth routes, resulting in very complex cavity shapes. An example of two such cavities are shown in Figures 76a and b, where the cavities are shown in red. An original, shape- based classification of the evolution of the cavities was proposed. As a result,