Publications in Scientific Journals:
"Sub-micrometer holotomography of multiphase metals";
ESRF Highlights (invited),
The microstructural characterization of multiphase materials by conventional 2D metallography can be insufficient if, for instance, connectivity between phases exists, or the orientation of constituents varies throughout the volume. For this, 3D characterisation tools are needed. Synchrotron microtomography has shown to be a powerful technique to reveal the architecture of materials. Furthermore, the coherence of the beam can be exploited applying quantitative phase contrast tomography or holotomography [ ] to image components with similar attenuation. The spatial resolution achievable by parallel beam synchrotron microtomography is about 1 Ám. This can be improved using magnifying optics [ ]. This has so far been achieved for samples with diameters < 100 Ám using relatively low energies. 3D imaging of engineering alloys requires high energies and representative sample sizes to correlate the properties with the microstructure achieved by the processing method.
Magnified synchrotron holotomography using a Kirkpatrick-Baez (KB) optics system [ ] was carried out at the nano-imaging end-station ID22NI for Al- and Ti-alloy samples of 0.4mm diameter. The focal point with a size of 80 nm (H) by 130 nm (V) and medium monochromaticity (E/E = 2x10-2) is produced by a set of multilayer coated crossed bent mirrors. Energies of 17.5 keV and 29 keV as well as effective pixel sizes of 60 nm and 51 nm were used for the Al-alloy and Ti-alloys, respectively. Phase retrieval for holotomography was achieved from recordings at four focal-point-to-sample distances.
synchrotron tomography, kirkpatrick baez optics, holotomography
Created from the Publication Database of the Vienna University of Technology.