Materials & Processes for Transport Technologies

Combining ultrafast X-ray cinetomography with in situ & operando environments we develop hierarchical, multiscale characterization methods for applications in automotive and aerospace fields. Current topics of materials imaging research at IPS include:

Synchrotron radiation-computed laminography (SRCL) acquires projection data sets similar to synchrotron computed tomography (SRCT), but it uses an inclined rotation axis at an angle θ < 90° instead of being perpendicular to the incoming beam (see figure). This makes SRCL suitable for 3D imaging of laterally extended (i.e. in the sheet directions perpendicular to the rotation axis) specimens.

The project LAMBDA applies SRCL to investigate the three-dimensional (3D) imaging of the microstructure inside flat sheet specimens evolving during material testing under such non-proportional loads.


Hypersonic re-entry of spacecraft into a planetary atmosphere introduces extreme loads on thermal insulation materials. Typically, there is a balance between the dimensioning of such thermal protection systems and the safety margins required for efficient flight design. Low density ablative TPS materials potentially provide signifcantly improvements to efficiency in insulation during high speed flights such as Moon return or Mars entry. 

In the present study, a portable high enthalpy facility has been designed in DLR Stuttgart and used for proof-of-principle tomography experiments at the KIT synchrotron.

In-Situ Ablation Experiments of Cork-based and Carbon Phenolic Thermal Protection Materials in an X-Ray Synchrotron Facility, Isil Sakraker, Archana Joshi, Hannah Böhrk, Daniel Haenschke and Angelica Cecilia, AIAA 2018-3588, Session: Ablation: Modeling, Experiments, and Applications II, DOI:

In modern gasoline direct injection engines, the fuel is (partially) superheated for a significant proportion of the time during operation. This means that the vapour pressure of the fuel, or at least of many of its components, is higher than the ambient pressure inside the engine during injection. If the excess fuel enthalpy cannot be removed by evaporation at the free surface of the spray, the liquid phase boiling creates new surfaces. This "flash boiling" process produces smaller droplets and can therefore be beneficial as an additional atomization mechanism. 


Within the project PN-Reduktion we employ high-speed X-ray radiography and shadowgraphy to characterize the physical development of fuel spray during its development and to correlate these data with flow-simulation models. For this a purpose-built mobile spray-injector chamber with an integrated high-speed camera setup will be realised.


Recent Publications
  1. Kong, X.; Helfen, L.; Hurst, M.; Hänschke, D.; Missoum-Benziane, D.; Besson, J.; Baumbach, T.; Morgeneyer, T. F. (2022). 3D in situ study of damage during a ‘shear to tension’ load path change in an aluminium alloy. Acta Materialia, 231, SArt.-Nr.: 117842. doi:10.1016/j.actamat.2022.117842
  2. Faragó, T.; Gasilov, S.; Emslie, I.; Zuber, M.; Helfen, L.; Vogelgesang, M.; Baumbach, T. (2022). Tofu : a fast, versatile and user-friendly image processing toolkit for computed tomography. Journal of Synchrotron Radiation, 29 (3). doi:10.1107/S160057752200282X
  3. Morgeneyer, T. F.; Khadyko, M.; Buljac, A.; Helfen, L.; Hild, F.; Benallal, A.; Børvik, T.; Hopperstad, O. S. (2021). On crystallographic aspects of heterogeneous plastic flow during ductile tearing: 3D measurements and crystal plasticity simulations for AA7075-T651. International journal of plasticity, 144, Art. Nr.: 103028. doi:10.1016/j.ijplas.2021.103028
  4. Tancogne-Dejean, T.; Roth, C. C.; Morgeneyer, T. F.; Helfen, L.; Mohr, D. (2021). Ductile damage of AA2024-T3 under shear loading: Mechanism analysis through in-situ laminography. Acta materialia, 205, Art.-Nr. 116556. doi:10.1016/j.actamat.2020.116556
  5. Bornschlegel, S.; Conrad, C.; Durst, A.; Welss, R.; Wensing, M.; Olbinado, M.; Helfen, L.; Baumbach, T. (2021). The influence of superheated injection on liquid and gaseous flow field of an experimental single-hole gasoline direct injection injector. International journal of engine research, 22 (2), 592–605. doi:10.1177/1468087419858464
  6. Ni, X.; Kopp, R.; Kalfon-Cohen, E.; Furtado, C.; Lee, J.; Arteiro, A.; Borstnar, G.; Mavrogordato, M. N.; Helfen, L.; Sinclair, I.; Spearing, S. M.; Camanho, P. P.; Wardle, B. L. (2021). In situ synchrotron computed tomography study of nanoscale interlaminar reinforcement and thin-ply effects on damage progression in composite laminates. Composites / B, Art.-Nr.: 108623. doi:10.1016/j.compositesb.2021.108623
  7. Castro, J.; Sket, F.; Helfen, L.; González, C. (2021). In situ local imaging and analysis of impregnation during liquid moulding of composite materials using synchrotron radiation computed laminography. Composites Science and Technology, 215, Art.-Nr.: 108999. doi:10.1016/j.compscitech.2021.108999
  8. Ziesche, R. F.; Robinson, J. B.; Markötter, H.; Bradbury, R.; Tengattini, A.; Lenoir, N.; Helfen, L.; Kockelmann, W.; Kardjilov, N.; Manke, I.; Brett, D. J. L.; Shearing, P. R. (2020). Editors’ choice—4D neutron and X-ray tomography studies of high energy density primary batteries: Part II. multi-modal microscopy of LiSOCl2 cells. Journal of the Electrochemical Society, 167 (14), Art. Nr.: 140509. doi:10.1149/1945-7111/abbfd9
  9. Heim, K.; Ershov, A.; Rack, A.; Banhart, J.; García-Moreno, F. (2020). Motion of liquid and stabilising particles in individual liquid aluminium alloy films. Journal of materials science, 55 (29), 14125–14136. doi:10.1007/s10853-020-05007-5
  10. Laiarinandrasana, L.; Morgeneyer, T. F.; Cheng, Y.; Helfen, L.; Le Saux, V.; Marco, Y. (2020). Microstructural observations supporting thermography measurements for short glass fibre thermoplastic composites under fatigue loading. Continuum mechanics and thermodynamics, 32 (2), 451–469. doi:10.1007/s00161-019-00748-4