In situ multi‐axial loading frame to probe elastomers using X‐ray scattering

International audienceAn in situ tensile-shear loading device has been designed to study elastomer crystallization using synchrotron X‐ray scattering at the Synchrotron Soleil on the DiffAbs beamline. Elastomer tape specimens of thickness 2 mm can be elongated by up to 500% in the longitudinal direction and sheared by up to 200% in the transverse direction. The device is fully automated and plugged into the TANGO control system of the beamline allowing synchronization between acquisition and loading sequences. Experimental results revealing the evolution of crystallization peaks under load are presented for several tension/shear loading sequences

Combination of X-ray synchrotron radiation techniques to gather information for clinicians

International audienceAmong the different techniques specific to synchrotron radiation, the combination of X-ray absorption spectroscopy with X-ray scattering experiments is a powerful tool to characterize samples with a capability to gather structural and electronic information at the cellular level. In the present contribution, selected examples making use of such techniques, point out as well the information that one can have access to. Via the presentation of the physicochemical data, this paper focuses on displaying the information that has a significant clinical character

Combined synchrotron X-rays and image correlation analyses of biaxially deformed W/Cu nanocomposite thin films on Kapton

International audienceAbstract In-situ biaxial tensile tests within the elastic domain were conducted with W/Cu nanocomposite thin films deposited on a polyimide cruciform substrate thanks to a biaxial testing machine developed on the DiffAbs beamline at SOLEIL synchrotron. The mechanical behavior of the nanocomposite was characterized at the micro-scale and the macro-scale using simultaneously synchrotron X-ray diffraction and digital image correlation techniques. Strain analyses for equi-biaxial and non equi-biaxial loading paths have been performed. The results show that the two strain measurements match to within 1 × 10-4 in the elastic domain for strain levels less than 0.3% and for both loading paths

Strain induced crystallization and melting of natural rubber during dynamic cycles

Strain-induced crystallization (SIC) of natural rubber (NR) is studied during dynamic cycles at high frequencies (with equivalent strain rates ranging from 7.2 s-1 to 290 s-1). The testing parameters are varied: the frequency, the temperature and the stretching ratio domain. It is found that an increase of the frequency leads to an unexpected form of the CI–¿ curve, with a decrease of the crystallinity during both loading and unloading steps of the cycle. Nevertheless, the interpretation of the curves needs to take into account several phenomena such as (i) instability of the crystallites generated during the loading step, which increases with the frequency, (ii) the memory of the previous alignment of the chains, which depends on the minimum stretching ratio of the cycle ¿min and the frequency, and (iii) self-heating which makes the crystallite nucleation more difficult and their melting easier. Thus, when the stretching ratio domain is above the expected stretching ratio at complete melting ¿melt, the combination of these phenomena, at high frequencies, leads to unexpected results such as complete melting at ¿min, and hysteresis in the CI–¿ curves.Peer ReviewedPostprint (author's final draft

Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

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Controlled biaxial deformation of nanostructured W/Cu thin films studied by X-ray diffraction

The deformation behaviour of 150. nm thick W/Cu nanocomposite deposited on polyimide substrates has been analysed under equi-biaxial tensile testing coupled to X-ray diffraction technique. The experiments were carried out using a biaxial device that has been developed for the DiffAbs beamline of SOLEIL synchrotron source. Finite element analysis has been performed to study the strain distribution into the cruciform shape substrate and define the homogeneous deformed volume. X-ray measured elastic strains in tungsten sub-layers could be carried out for both principal directions. The strain field was determined to be almost equi-biaxial as expected and compared to finite element calculations