Mechanical performance of triply periodic minimal surface structures with a novel hybrid gradient fabricated by selective laser melting

Triply periodic minimal surface (TPMS) structures have been extensively investigated for their excellent mechanical properties and lightweight potential. In this study, a new hybrid gradient (HG) TPMS structure was proposed by combining geometrically deformed gradient (GDG) and volume fraction gradient (VFG). All designed structures were fabricated by selective laser melting (SLM) using Ti-6Al-4V. They were investigated experimentally in terms of deformation behavior, stress–strain curve and energy absorption. The results demonstrated that the GDG structure can develop a better deformation mode to enhance the energy absorption, while the VFG structure can help to reduce the initial peak force and delay the densification point. Most importantly, the hybridization of these two gradients can both greatly enhance the energy absorption capacity and delay the densification point. Compared with the uniform structures, the hybrid gradient structures can almost double the energy absorption under compression. The results of this research may provide valuable insights for the design of high-performance energy-absorbing structures in the future.