Lightweight Design and Additive Manufacturing of a Fatigue-Critical Automotive Component

Metal additive manufacturing is finding growing applicability in motorsports and high performance car sectors. Laser-Powder Bed Fusion (L-PBF) is the most developed AM technology for lightweight aluminum alloys producing near-net-shape components of complex geometry that achieve outstanding lightweight targets. A key issue in the widespread industrial acceptability of L-PBF is the structural integrity of these lightweight components when subjected to dynamic loading conditions because it requires in-depth knowledge of the fatigue behavior of L-PBF aluminum under the combined effect of stress gradients, residual stresses, surface condition and process-induced internal defects. This contribution overviews the presentation and application of an integrated design workflow that includes the following phases: i) a topological optimization phase to achieve lightweight targets, ii) a design for additive manufacturing phase supported by process simulation to optimize part production, iii) actual part fabrication in an industrial-grade L-PBF system using AlSi10Mg alloy powder followed by post fabrication heat treatment iv) production and fatigue testing of witness specimens providing relevant design data; v) fatigue testing of the parts to determine actual performance and vi) final assessment of the design know-how developed for fatigue-critical additively manufactured metal components.