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

The study numerically investigates the deformation and fracture of the eutectic alloy AlSi12 produced by wire-feed electron beam additive manufacturing. A "top-down" approach is implemented for the numerical-experimental determination of local plastic and strength properties of materials. The alloy's microstructure of different scales is experimentally examined 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 meso-levels to extract the mechanical properties of the aluminum in the eutectic material and dendrites. With the use of the experimental flow curve and nanoindentation data at the macrolevel, the hardening functions and ultimate strains for the layer and interlayer materials are determined by numerically simulating the layered structure tension. The layer properties obtained and nanoindentation data are then used to derive the properties of the aluminum in the eutectic material and dendrites by simulating the dendritic structure tension at the mesoscopic scale. The derived plastic and strength characteristics of the aluminum and the eutectic material are applied to numerically analyze the heterogeneous plastic flow and cracking in the dendritic structure with an interlayer containing micron-sized silicon particles.