Search

Metallic materials processing such as rolling, extrusion or forging often involves high‐temperature deformation. Usually under such conditions the samples are characterized post mortem, under pseudo in situ conditions with interrupted tests, or in situ with a limited strain rate. A full in situ 3D characterization, directly during high‐temperature deformation with a prescribed strain‐rate scheme, requires a dedicated sample environment and a dedicated image‐analysis workflow. A specific sample environment has been developed to enable highly controlled (temperature and strain rate) high‐temperature deformation mechanical testing to be conducted while performing in situ tomography on a synchrotron beamline. A dedicated digital volume correlation algorithm is used to estimate the strain field and track pores while the material endures large deformations. The algorithm is particularly suitable for materials with few internal features when the deformation steps between two images are large. An example of an application is provided: a high‐temperature compression test on a porous aluminium alloy with individual pore tracking with a specific strain‐rate scheme representative of rolling conditions. [ABSTRACT FROM AUTHOR]

As one of the most important analysis techniques for non-destructive imaging, X-ray tomography has been widely used in materials science, medical science, and industry to evaluate the behavior of porous materials. By using this method, a three dimensional volume can be inspected in order to visualize in situ the progress of damage in materials and this can be analyzed qualitatively and quantitatively. In the present study, we have used X-ray tomography to investigate the fracture behavior of an ERG open cell aluminum foam. The process of damage development of a sample undergoing tension and the relation between the inter-metallics and the cracks can be observed totally by the X-ray tomography set-up. Local tomography has in particular been used to image the microstructure at high resolution. A finite element model has also been developed in order to simulate this process of the damage using the 3D data obtained by the tomography. [ABSTRACT FROM AUTHOR]

Ultrafast synchrotron microtomography has been used to study in situ and in real time the initial stages of silicate glass melt formation from crystalline granular raw materials. Significant and unexpected rearrangements of grains occur below the nominal eutectic temperature, and several drastically different solid-state reactions are observed to take place at different types of intergranular contacts. These reactions have a profound influence on the formation and composition of the liquids produced, and control the formation of heterogeneities. [ABSTRACT FROM AUTHOR]