Compressive behavior and energy absorption of 3D-printed AlSi10Mg with Kelvin-derived lattice structures fabricated by laser powder bed fusion

A novel Kelvin-derived unit cell was developed via shell extraction and face-centered perforation. Based on this design concept, multicellular units with distinct structural characteristics were constructed by differentiating the load-bearing contact geometries on the surfaces of the unit cells. Subsequently, lattice models were developed using simple stacking and local cutting strategies, and AlSi10Mg specimens were fabricated via laser powder bed fusion (LPBF) followed by heat treatment. Quasi-static compression tests, finite element simulations, and microstructural analyses were conducted to systematically investigate the compressive mechanical behavior, energy absorption performance, and failure mechanisms of the specimens. The results demonstrate that lattice specimens with different multicellular topologies exhibit markedly different compressive mechanical responses. Among them, lattices constructed based on specific edge-dominated load-bearing modes show the optimal energy absorption performance, maintaining an energy absorption efficiency of approximately 75% after yielding. Across all configurations, the maximum compressive strength of the simply stacked lattices is limited to 43 MPa, whereas that of the locally cut lattices reaches up to 144 MPa. The local cutting strategy significantly enhances the load-bearing contribution of the outermost units, leading to a compressive strength increase of approximately 180%–460% compared with the simply stacked design for identical multicellular topologies. Furthermore, finite element simulations combined with microscopic fracture observations were employed to elucidate the failure mechanisms. The results indicate that, under the present design and fabrication conditions, the pore-wall units predominantly undergo a multistage brittle failure process governed by the combined effects of bending and tensile deformation.