Computational Mesomechanics of Materials Using the Example of Additively Manufactured Eutectic Aluminum-Silicon Alloy

The study numerically investigates deformation and fracture of the eutectic AlSi12 alloy produced by wire-feed electron beam additive manufacturing. A top-down approach is implemented for the numerical and experimental determination of local plastic and strength properties of materials. The alloy structure is experimentally examined on different scales using optical microscopy. Mechanical uniaxial tensile and nanoindentation tests are performed. Based on the experimental data, the finite element models of the layered structure at the macrolevel and dendritic structure at the mesolevel are created. The top-down analysis involves sequential numerical simulations at the macro- and mesolevels to extract the mechanical properties of aluminum in the eutectic material and dendrites. Based on the experimental flow curve and nanoindentation data, hardening functions and ultimate strains are determined for the layer and interlayer materials by numerically simulating the layered structure tension on the macroscale. The obtained layer properties and nanoindentation data are then used to derive the properties of aluminum in the eutectic and dendrites by simulating the dendritic structure tension on the mesoscale. The derived plastic and strength characteristics of aluminum and the eutectic are used to numerically analyze heterogeneous plastic flow and cracking in the dendritic structure with an interlayer containing micron-sized silicon particles.