Influence of manufacturing geometric defects on the mechanical properties of AlSi10Mg alloy fabricated by selective laser melting

Abstract

The tensile behavior of bulk AlSi10Mg components, fabricated by selective laser melting (SLM), was investigated by uniaxial tensile testing and image-based finite element simulation. The initial morphological features of the structures were imaged by micro X-ray tomography. Moreover, the reconstructed model and as-designed model were compared to quantify the process-induced defects, which remained unavoidable due to complex manufacturing processes. The un-melted AlSi10Mg powders, sticking to the melting pool after condensation, intensified the deviation of side edges. Futhermore, the unevenly distributed process-induced defects resulted in anisotropic mechanical properties of AlSi10Mg alloy. Two finite element models were developed from X-ray tomography images and CAD model, which were simulated by finite element solver ABAQUS/Standard to discuss the effect of initial morphological features on the mechanical behavior of these samples. The geometric defects have slightly reduced Young's modulus and yield strength, but remarkably increased the equivalent plastic strain of the bulk structures. Furthermore, the ultimate strength and elongation, predicted by the image-based finite element model and the ductile failure criterion, was much lower than the values predicted by the as-designed model due to the influence of geometric defects.