A Numerical Study of the Stress-Strain Behavior of Additively Manufactured Aluminum-Silicon Alloy at the Scale of Dendritic Structure

This paper numerically investigates the stress-strain behavior at the scale of the dendritic structure in an aluminum-silicon alloy additively manufactured by selective laser melting. The stress-strain state in the eutectic phase is studied under the assumption that the continuum mechanics principles are applicable on the scales considered. The averaged characteristics of the eutectic phase are used as input parameters for modeling the deformation of a dendritic structure fragment of a grain, for which significant structural elements are introduced explicitly on each considered scale. It is shown that, on the one hand, the eutectic matrix in dendritic grains of additively manufactured aluminum-silicon alloys inhibits plastic deformation in the dendrite, while on the other it can be a source of stress concentration and microdefect formation already at the early stage of deformation.