Correlative microscopy using SEM based nano-CT

Abstract

Besides electron imaging in scanning electron microscopy (SEM), techniques like energy dispersive X-ray spectroscopy (EDX) or electron backscatter diffraction (EBSD) are widely established. With integration of a target holder and a pixelated X-ray detector, X-ray computed tomography (CT) in SEM can be realized and extends the modalities of materials characterization in one instrument. For nano-CT mode, an electron beam is focused on a suitable target leading to X-ray emission. While passing through a specimen, X-rays are differently attenuated depending on their material properties and detected by a direct converting X-ray detector afterward. Presented is a SEM-based nano-CT called XRM-II nanoCT and different applications of correlative microscopy using electron imaging, energy dispersive X-ray spectroscopy and CT. Besides multiscale investigation on materials for fuel cells and electrolysers by 3D visualization with micro- and nano-CT, nano-CT characterization of a catalytic converter with additional chemical analysis is depicted. At last, time-resolved imaging of morphology changes in an annealed Al alloy using nano-CT is presented. Results show grain coarsening as well as precipitations in the range of 200 – 1200 nm.