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Phase-contrast three-dimensional tomograms showing in unprecedented detail the mechanical response of a micro-composite subjected to a mechanical compression test are reported. The X-ray ptychography images reveal the deformation and fracture processes of a 10 μm diameter composite, consisting of a spherical polymer bead coated with a nominally 210 nm metal shell. The beginning delamination of the shell from the core can be directly observed at an engineering strain of a few percent. Pre-existing defects are shown to dictate the deformation behavior of both core and shell. The strain state of the increasingly compressed polymer core is assessed quantitatively through the local densification at sub-micron resolution, supported by finite element analysis. Nanoscale mechanics is of rapidly growing importance in materials science, biotechnology and medicine, and this study demonstrates the use of coherent X-ray microscopy as a powerful tool for in situ studies of the mechanical properties of nanostructured devices, structures, and composites. Ptychographic X-ray microscopy can be used for quantitatively studying the mechanical properties of microscale composites. Phase-contrast three-dimensional tomograms reveal with unprecedented detail the mechanical response, including delamination, densification and fracture, of a polymer-core/silver-shell micro-composite subjected in situ to a mechanical compression test.

Small-angle X-ray scattering tomography has for the first time been used toinvestigate the spatially resolved orientation distribution of talc particles in asample of injection molded isotactic polypropylene, where the particles had apreferred orientation along the axis of the injection. The scattering patternsin the direction perpendicular to the rotation axis of the tomography scanwere used to retrieve the orientation distribution in a 2D cross section of thesample.Two different methods are presented, one using a numerical approach ofsimulated annealing and one method using a linear set of equations to findthe distances the X-ray beam travels through the different orientation regions.The method of simulated annealing showed little to no promise inretrieving the orientation distribution while the method using a linear setof equations is successful at retrieving the main features of the orientationdistribution. The resolution is however not yet good enough to distinguishfine details inside the sample.It is believed that with further work on the model used and additional constraintson the reconstruction algorithm higher precision in the retrievedorientation distribution can be achieved.