AlSi10Mg plate-lattice structures fabricated by laser powder bed fusion exhibiting high specific energy absorption

Theoretical studies have shown that plate-lattice structures exhibit exceptional mechanical properties such as high strength-to-weight ratios. Their fabrication, however, is challenging and has only been realized for metals via the Laser Powder Bed Fusion (LPBF) process. A deeper understanding of the deformation mechanisms of LPBF fabricated plate-lattice structures, including their post-yielding and energy absorption characteristics, is needed to evaluate their applicability in defense, aerospace, and biomedical industries. In this study, AlSi10Mg plate-lattice structures with four unit cell topologies were fabricated using LPBF and tested in quasi-static compression to determine mechanical properties, deformation behaviors, and energy absorption capabilities. Microcomputer tomography revealed surface variations resulting from adhered powder and dross formation were comparable in scale to plate thicknesses. Tested plate-lattices experience primarily stretch-dominant deformation consistent with theoretical Gibson-Ashby models. Stretch-dominant deformation is maintained for large compressive strains post-yielding until brittle fracture occurs in unit cell layers or diagonal bands, leading to high localized strength. For the simple cubic geometry, high yield stresses that were maintained post-yielding resulted in the highest specific energy absorption yet observed in lattice materials, reaching up to 27.2 J/g at a density of 1.23 g/cc. This research highlights AlSi10Mg plate-lattices as excellent candidates for light-weight energy absorption applications.