Filtern
Erscheinungsjahr
Dokumenttyp
Schlagworte
- Neutron imaging (7)
- Neutron tomography (7)
- Computed tomography (4)
- Fuel cell (4)
- Neutron radiography (4)
- Tomography (4)
- Computertomographie (3)
- Neutronen-Tomographie (3)
- Phase distribution (3)
- Brennstoffzellen (2)
- Catalyst (2)
- Computer-Tomographie (2)
- Darkfield imaging (2)
- Electron tomography (2)
- Elektronen-Tomographie (2)
- Geometrical effect (2)
- Hydrogen diffusion (2)
- Hydrogen embrittlement (2)
- Magnetic domains (2)
- Neutronentomographie (2)
- Reconstruction algorithm (2)
- Rectangular cross-section (2)
- Rekonstruktionsalgorithmen (2)
- Torsion (2)
- Water management (2)
- X-ray compton scattering (2)
- X-ray imaging (2)
- 4D tomographic data (1)
- Backlighting (1)
- Blister (1)
- Bragg-edge (1)
- Bragg-edge imaging (1)
- Brennstoffzelle (1)
- Cells (1)
- Compression effect (1)
- Comptonstreuung (1)
- Debye-Waller-Faktor (1)
- Diffraction contrast neutron imaging (1)
- Diffusion (1)
- Digital detector array (1)
- Elektronentomographie (1)
- Fiber composites (1)
- Full-field phase tomography (1)
- Gas diffusion layer (1)
- Gas evolution (1)
- Grating interferometry (1)
- Hydrogen (1)
- Imaging (1)
- In situ (1)
- In-Situ-Radiologie (1)
- Instrumentation for neutron sources (1)
- Iron (1)
- Laser powder-bed fusion (1)
- Lithium-ion battery (1)
- Manifold stack (1)
- Materialcharakterisierung (1)
- Metal foam microstructure (1)
- Multi-energy CT (1)
- Neutron computed tomography (1)
- Neutron detectors (cold, thermal, fast neutrons) (1)
- Neutronen-Radiographie (1)
- Neutronenlaminographie (1)
- Nneutron imaging (1)
- Non-destructive testing (1)
- PEM fuel cell (1)
- Phase transformation (1)
- Polymer electrolyte membrane fuel cell (1)
- Polymer electrolyte membrane fuel cell (PEMFC) (1)
- Preferential orientation (1)
- Primary Battery (1)
- Radiography (1)
- Radiology (1)
- Reconstruction algrorithm (1)
- Room-temperature (1)
- Röntgen-Kanten-Tomographie (1)
- Shearing gratings (1)
- Spectral CT (1)
- Steel (1)
- Stromdichtemessung (1)
- Synchrotron (1)
- Synchrotronstrahlung (1)
- Talbot-Lau (1)
- Talbot-Lau interferometer (1)
- Talbot-Lau neutron tomography (1)
- Texture (1)
- Thermal runaway (1)
- Three-dimensional data quantification (1)
- Tomographic reconstruction (1)
- Tomographische Rekonstruktionsalgorithmen (1)
- Two-phase flow (1)
- Wassermanagement (1)
- Water transport (1)
- X-ray CT (1)
- X-ray radiography (1)
- X-ray tomography (1)
- Zerstörungsfrei (1)
- cold neutrons (1)
- iron embrittlement (1)
- neutron imaging (1)
- neutron instrumentation (1)
Organisationseinheit der BAM
Die Computer-gestützte Laminografie (CL) wurde als komplementäre Methode zur Computertomografie für die dreidimensionale Bildgebung von lateral ausgedehnten Objekten entwickelt. Ursprünglich für medizinische Zwecke verwendet, wurde diese Methode kürzlich als zerstörungsfreie nicht-invasive Methode nicht nur in der Materialforschung, sondern auch mit steigendem Interesse für kunsthandwerkliche und historische Objekte eingesetzt. Hier wird die Computer-gestützten Laminografie mit polychromatischer Neutronenstrahlung an einer historischen Tsuba eingesetzt, einem Stichblatt eines japanischen Schwerts. Eine Analyse der Lötstellen gibt Rückschlüsse auf das Herstellungsverfahren. Zudem wurden unterschiedliche Materialsysteme gefunden, vermutlich um dem Tsuba lokal eine höhere Stabilität zu verleihen. Die Messungen wurden an der Imaging-Beamline CONRAD-2 an der Neutronenquelle BER 2 des Helmholtz-Zentrums Berlins (HZB) durchgeführt.
A systematic, nature-inspired chemical engineering approach is employed to solve the issue of flooding in electrochemical devices. The mechanism of passive water transport utilized by lizards living in arid environments is leveraged to design flow-fields with a microchannel structure on their surface, through which capillary pressure rapidly removes the water generated in the electrochemical device. This water management strategy is implemented in proton exchange membrane fuel cells (PEMFCs) with a lunginspired flow-field, which ensures uniform distribution of reactants across the catalyst layer. Jointly, this nature-inspired approach results in flood-free, stable operation at 100% RH and a B60% increase in current (B1.9 A cm-2) and peak power density (B650 mW cm−2) compared to current PEMFCs with a flood-prone, serpentine flow-field (B0.8 A cm-2 and 280 mW cm-2, respectively). This significant advance allows for PEMFC operation at fully humidified conditions.
Metastable austenitic stainless steel (304L) samples with a rectangular cross-section were plastically deformed in torsion during which they experienced multiaxial stresses that led to a complex martensitic phase distribution owing to the transformation induced plasticity effect. A three-dimensional characterization of the phase distributions in these cm-sized samples was carried out by wavelength-selective neutron tomography. It was found that quantitatively correct results are obtained as long as the samples do not exhibit any considerable preferential grain orientation. Optical microscopy, electron backscatter diffraction, and finite element modeling were used to verify and explain the results obtained by neutron tomography. Altogether, neutron tomography was shown to extend the range of microstructure characterization methods towards the meso- and macroscale.
This study was carried out to investigate the neutron transmission signal as a function of sample temperature during a welding process. A theoretical description that includes the Debye-Waller factor was used to describe the temperature influence on the neutron crosssections. Neutron imaging using a monochromatic beam helps to observe transmission variations related to the material temperature. In-situ neutron imaging of welding experiments show the distribution of the temperature in bulk steel samples. The performed finite element modelling of expected temperature distributions shows good agreement with the obtained experimental data.