Structure–property relationships in PBF-LB/M AlSi10Mg TPMS lattices: coupled effects of topology, relative density, and heat treatment on compressive behavior

Triply periodic minimal surface (TPMS) lattices offer strong potential for lightweight structural and energy-absorbing applications, however, the coupled influence of lattice topology, relative density, and post-processing-induced microstructural changes on their mechanical response remains insufficiently understood. In this study, Gyroid, Diamond, Primitive, and IWP AlSi10Mg TPMS lattices were fabricated via laser powder bed fusion (PBF-LB/M) at three relative densities and investigated in both as-built and EOS T6 heat-treated conditions. Quasi-static compression testing up to 50% strain was performed to evaluate stiffness, strength, deformation behavior, and energy absorption. While increasing relative density consistently enhanced stiffness, strength, and specific energy absorption, the magnitude and scaling of these improvements were found to depend strongly on topology and material condition. Heat treatment reduced yield strength and peak stress, but also altered deformation behavior and energy absorption characteristics in interaction with the other design variables. The results reveal that the compressive performance of TPMS lattices cannot be accurately described through independent effects of topology, density, or heat treatment alone, but instead emerges from their coupled interactions. This study therefore provides new insight into the structure–property relationships governing additively manufactured TPMS lattices and offers design considerations within the tested parameter space for tailoring mechanical performance through the coupled control of architecture and material condition.