Eigenstrain and neighbourhood effects on the lattice strain distribution within BCC polycrystals – key for materials design and modelling

The relationship between macroscopic and microscopic stresses is central for a quantitative understanding of the mechanical behaviour of structural materials. The goal of this proposal is the validation and improvement of micromechanical methods to estimate local stresses for BCC polycrystalline materials. A particular focus lies on the Maximum-Entropy method (MEM) which is capable of predicting local stresses based on macroscopic mechanical properties and microstructural information. We propose to implement Diffraction Contrast Tomography (DCT) to determine the shape, arrangement, orientation and average elastic strain tensor of a representative ensemble of individual grains within a polycrystal for increasing tensile loading. Based on this unique experimental dataset, simulations and analytical methods can be combined to validate the MEM, yielding a new computationally extremely efficient approach for hierarchical materials informatics.