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TiAl alloys are increasingly used as a lightweight material, for example in aero engines, which also leads to the requirement for suitable repair techniques. Transient liquid phase bonding is a promising method for the closure of cracks (in non-critical or non-highly loaded areas). The brazing solder Ti-24Ni was investigated for brazing the alloy Ti-45Al-5Nb-0.2B-0.2C (in at. %). After brazing, the joint exhibits different microstructures and phase compositions. The transient liquid phase bonding process was investigated in the middle of the joint region in situ to acquire time resolved information of the phases, their development, and thus the brazing process. These investigations were performed using high-energy X-ray diffraction at the “High-Energy Materials Science” beamline HEMS, located at the synchrotron radiation facility PETRA III at DESY in Hamburg, Germany. For this, we used an induction furnace, which is briefly described here. During the analysis of the diffraction data with Rietveld refinement, the amount of liquid was refined with Gaussian peaks and thus could be quantified. Furthermore, while brazing four different phases occurred in the middle of the joint region over time. Additionally, the degree of ordering of the βo phase was determined with two ideal stoichiometric phases (completely ordered and disordered). Altogether, the phase composition changed clearly over the first six hours of the brazing process.

Developments in X-Ray Tomography XII : [Proceedings] - SPIE, 2019. - ISBN 97815106291969781510629202 - doi:10.1117/12.2530445 Developments in X-Ray Tomography XII, San Diego, United States, 11 Aug 2019 - 15 Aug 2019; SPIE 1111318 pp. (2019). doi:10.1117/12.2530445, A load frame for in situ mechanical testing is developed for the microtomography end stations at the imaging beamline P05 and the high-energy material science beamline P07 of PETRA III at DESY, both operated by the Helmholtz- Zentrum Geesthacht. The load frame is fully integrated into the beamline control system and can be controlled via a feedback loop. All relevant parameters (load, displacement, temperature, etc.) are continuously logged. It can be operated in compression or tensile mode applying forces of up to 1 kN and is compatible with all contrast modalities available at IBL and HEMS i.e. conventional attenuation contrast, propagation based phase contrast and differential phase contrast using a grating interferometer. The modularity and flexibility of the load frame allows conducting a wide range of experiments. E.g. compression tests to understand the failure mechanisms in biodegradable implants in rat bone or to investigate the mechanics and kinematics of the tessellated cartilage skeleton of sharks and rays, or tensile tests to illuminate the structure-property relationship in poplar tension wood or to visualize the 3D deformation of the tendonbone insertion. We present recent results from the experiments described including machine-learning driven volume segmentation and digital volume correlation of load tomography sequences., Published by SPIE

Developments in X-Ray Tomography XI : [Proceedings] - SPIE, 2017. - ISBN 9781510612396 - doi:10.1117/12.2275121 Developments in X-Ray Tomography XI, San Diego, United States, 6 Aug 2017 - 10 Aug 2017; Proceedings of SPIE 10391, 103910 (2017). doi:10.1117/12.2275121, Permanent implants made of titanium or its alloys are the gold standard in many orthopedic and traumatological applications due to their good biocompatibility and mechanical properties. However, a second surgical intervention is required for this kind of implants as they have to be removed in the case of children that are still growing or on patient’s demand. Therefore, magnesium-based implants are considered for medical applications as they are degraded under physiological conditions. The major challenge is tailoring the degradation in a manner that is suitable for a biological environment and such that stabilization of the bone is provided for a controlled period. In order to understand failure mechanisms of magnesium-based implants in orthopedic applications and, further, to better understand the osseointegration, screw implants in bone are studied under mechanical load by means of a push-out device installed at the imaging beamline P05 of PETRA III at DESY. Conventional absorption contrast microtomography and phasecontrast techniques are applied in order to monitor the bone-to-implant interface under increasing load conditions. In this proof-of-concept study, first results from an in situ push-out experiment are presented., Published by SPIE, Bellingham, Wash.

The Imaging Beamline (IBL) P05 is operated by the Helmholtz-Zentrum Geesthacht and located at the DESY storage ring PETRA III. IBL is dedicated to X-ray full field imaging and consists of two experimental end stations. A micro tomography end station equipped for spatial resolutions down to 1 µm and a nano tomography end station for spatial resolutions down to 100 nm. The micro tomography end station is in user operation since 2013 and offers imaging with absorption contrast, phase enhanced absorption contrast and phase contrast methods. We report here on the current status and developments of the micro tomography end station including technical descriptions and show examples of research performed at P05.

Conventional absorption-based imaging often lacks in good contrast at special applications like visualization of soft tissue or weak absorbing material in general. To overcome this limitation, several new X-ray phase-contrast imaging methods have been developed at synchrotron radiation facilities. Our aim was to establish the possibility of different phase-contrast imaging modalities at the Imaging Beamline (IBL, P05) and the High Energy Material Science beamline (HEMS, P07) at Petra III (DESY, Germany). Here we present the instrumentation and the status of the currently successfully established phase-contrast imaging techniques. First results from measurements of biomedical samples will be presented as demonstration.

Developments in X-Ray Tomography IX, San Diego, California, USA, 18 Aug 2014 - 20 Aug 2014; Proceedings of SPIE 9212, 92120O (2014). doi:10.1117/12.2061768, The imaging beamline (IBL/P05) operated by Helmholtz Zentrum Geesthacht (HZG) at the DESY PETRA III storage ring consists of two experimental stations: A micro tomography and a nano tomography end station. Here an overview of the experimental setups and the data acquisition will be given. In addition some first results out of the wide range of applications using the micro tomography station at P05 will be shown. Furthermore, we present first results of the nano tomography end station. These were obtained with an x–ray microscopy setup, which currently operates at energies of 17.4 and 30 keV using polymer compound refractive lenses (CRLs) and rolled prism lenses. Taken together these results clearly show the high potential of the newly built imaging beamline IBL., Published by SPIE, Bellingham, Wash.