Design, production, and fatigue testing of an optimized structural component made of L-PBF AlSi10Mg

Laser Powder Bed Fusion is considered as one of the most innovative manufacturing technologies and has rapidly gained interest in industry because it allows to produce near-net-shape metal components characterized by complex geometry. The structural integrity of parts with geometrical characteristics driven by optimized lightweight trade-offs should be verified before they are considered for critical applications in sectors such as automotive and aerospace. In this work a case study is presented: topology optimization is performed on a down-scaled automotive component with target definition of in terms of weight to stiffness ratio. An integrated design workflow of a metal AM part (i.e., from geometrical topological optimization to AM process simulation before production), ii) the actual part fabrication in an industrial-grade L-PBF system using the AlSi10Mg alloy powder and iii) structural qualification by fatigue testing of actual parts. The material selected for the study is AlSi10Mg, an alloy typically used in the automotive field. An SLM500 system with process parameters of 50 mu m as layer thickness is used to produce components to be fatigue tested in the laboratory. Knowledge of the link between technology-dependent factors and the fatigue strength was determined with a specific test methodology using miniature specimens. The anisotropic fatigue behavior obtained with specimens revealed the key role of residual stresses for as-built L-PBF AlSi10Mg. Prediction of the fatigue response of the optimized L-PBF part benefited from extensive modeling and simulation activities and ad-hoc material testing. (C) 2021 The Authors. Published by Elsevier B.V.