Hybrid plate-TPMS lattice metamaterials with exceptional stiffness and strength

This study introduces new hybrid (multi-topology) lattice metamaterials, combining both plate-lattices and triply periodic minimal surface (TPMS) sheet-based lattices. These hybrids are combinations of simple cubic (SC) or face-centred cubic (FCC) plate-lattices and Schwarz-Primitive (SP), Gyroid (G), or Diamond (D) TPMS lattices, forming six distinctive lattices; namely; SP + SC (SPSC), G + SC (GSC), D + SC (DSC), SP + FCC (SPFCC), G + FCC (GFCC), and D + FCC (DFCC). These hybrids and their parent ones were additively manufactured for investigating their mechanical properties experimentally and numerically. Results revealed that hybridising SC plate-lattice with SP, G, and D TPMS lattices yield exceptional stiffness and strength that well surpass stiffest and strongest previously reported hybrid lattices. It is shown that GSC as stiffest among all tested configurations followed by SPSC and DSC. Furthermore, DSC outperformed all configurations after yielding, showcasing larger yield strength, plateau stress, and energy absorption. SC + TPMS lattices drastically outperformed both TPMS and FCC + TPMS lattices, with up to 171% increase in stiffness, 125% increase in strength, and 117% increase in energy absorption compared to its TPMS counterpart. This study showed how the effect of hybridisation can be either substantially beneficial or detrimental, where SC + TPMS lattices proved promising mechanical properties, making them great candidates in stiff and strong lightweight applications.