Laser Powder Bed Fusion of AlSi10Mg lattice for structural applications

Additive manufacturing (AM) includes a series of production technologies that build three-dimensional components layer over layer starting from digital CAD models, enabling the fabrication of parts often impossible or too expensive to produce using conventional methods. Additive manufactured lightweight and topology optimized parts are particularly advantageous for aerospace, automotive, biomedical and energy applications. Among AM techniques, Laser Powder Bed Fusion (LPBF) is widely used in metal additive manufacturing to create complex geometries with high precision. The adoption of Design for Additive Manufacturing (DfAM) principles, including functional grading, further enhances the potential of AM by allowing spatial variation of structural properties, optimizing stiffness, strength, and energy absorption of the components. This thesis investigates the design, fabrication, and mechanical characterization of AlSi10Mg functionally graded lattice structures with varying strut and wall thickness along their length. Three types of Triply Periodic Minimal Surfaces lattice topologies were selected to fabricate compression specimens via LPBF. Mechanical performance was evaluated through quasi-static compression tests, obtaining elastic modulus, ultimate compressive strength and energy absorption of each sample. High-resolution computed tomography (CT) was used to perform porosity analysis on some of the as-built samples, verifying dimensional accuracy and identifying potential defects. Also, fracture analysis was conducted resorting to Scanning Electron Microscopy (SEM). The direct comparison of Diamond, Schwarz Primitive and Neovius structures fabricated under identical process conditions but with varying design parameters, addresses a critical gap and provides valuable insights to guide the selection of the best-suited lattice architecture for specific loading conditions and applications.