Fig. 3: Multiscale correlative tomography workflow applied to detect damage nucleation and evolution inside the fine equiaxed zone (FQZ).

a Distribution of equivalent plastic strain (PEEQ) across the weld zone predicted by an image-based 3D finite element (FE) simulation where the applied stress σ = 60 MPa perpendicular to the weld. b 3D volume renderings (pores rendered green and cracks yellow) acquired at two loading stages by in situ tensile synchrotron micro computed tomography (microCT) to determine the preferential damage nucleation site and damage evolution. c Post-mortem fractography of a failed welded joint by scanning electron microscope (SEM). d NanoCT volume renderings of the spatial distribution of intergranular phases prior to deformation. e Quantitative analysis of the projected areas of nucleated micro-voids when σ = 270 MPa. f Spatial distribution of intergranular phases and nucleated micro-voids by high-resolution synchrotron X-ray nanoCT when σ = 270 MPa showing the large-sized long-range connected voids (green), the intergranular phases (yellow) and the nucleated micro-voids (red). g NanoCT visualization of the interaction between the intergranular phases (yellow) and nucleated micro-voids (red). h Intergranular phase inducing micro-void nucleation observed by (transmission electron microscopy-energy dispersive spectrometry) TEM-EDS, showing TEM image, selected area electron diffraction (SAED) and EDS spectra.