Synchrotron imaging and diffraction for In Situ 3D characterization of polycrystalline materials
Résumé
Determining polycrystalline microstructure-property relationships is directly linked to the ability to observe both the microstructure and the deformation/failure mechanisms concurrently. This field is moving rapidly with new means of observing the microstructure non-destructively in 3D (such as diffraction contrast tomography (DCT), among others) and subsequent in situ imaging (scanning electron microscope (SEM), digital image correlation (DIC) on the specimen surface or CT for internal damage). In recent years, continuum crystal plasticity has proved to be a powerful tool to interpret experimental results obtained in the deformation of metallic polycrystals. All these new experimental developments can provide 3D microstructure images to serve as input for finite-element calculations of the local/global mechanical properties. The construction of a realistic mesh with tetrahedra finite elements from a multi-labeled tomographic image representing a polycrystalline microstructure is a non-trivial procedure. In the simplest case, the microstructure image is composed of only one slice. This is the case of thin polycrystalline films.