Investigation of Strain Localization in Additively Manufactured AlSi10Mg Using CPFEM

The effect of different grain morphologies achieved by separate scanning strategies in powder bed fusion on the tensile behavior of additively manufactured AlSi10Mg was investigated using experiments and crystal plasticity finite element method based simulations. Inhomogeneous and coarse grain structure for scanning without rotation (X0) led to higher tensile strength while scanning with 67-degree rotation per layer (X67) showed higher ductility. Microstructural information from electron backscatter diffraction about the grain size and aspect ratio of grains for the two conditions was used to generate a representative volume element sing Voronoi tessellation in Matlab. The generated statistically equivalent microstructure was imported into ABAQUS FE solver with the help of python scripting. Symmetry boundary conditions were applied on the imported RVE. Crystal plasticity model was implemented in ABAQUS on the statistically equivalent microstructure through UMAT and the model parameters were calibrated through optimization using Genetic Algorithm. CPFEM simulations were able to capture the tensile response of X0 and X67 samples and showed higher stress accumulation in the former compared to the latter that can explain the early failure of the X0 sample.