Towards a performance map of gyroid structures for varying cell size: Trade-off between carbon footprint and structural performance

Additive manufacturing (AM) has emerged as a transformative technology enabling the production of complex geometries that reduce component mass and improve performance, particularly through the integration of lattice structures. These lightweight architectures, characterised by a high surface-to-volume ratio, are increasingly being analysed and integrated into various technical applications due to their exclusive properties. Among the most promising configurations are Triply Periodic Minimal Surfaces (TPMS), especially gyroid structures, which offer structural and functional advantages. This study builds on new performance metrics for lattice structures that combine productivity and sustainability, addressing the growing need to prioritise carbon footprint considerations in engineering design. The research also critiques existing environmental assessment methods for their inability to fully capture the unique capabilities of advanced AM technologies. The influence of cell size variation in gyroid lattice structures fabricated via Laser Powder Bed Fusion of AlSi10Mg is evaluated on both environmental impact and productivity. The study includes four cubic specimens with cell dimensions varying from 4 to 12 mm but consistent wall thickness and performs a comparative cradle-to-gate life cycle assessment to evaluate the environmental impact, particularly in terms of carbon emissions. The results quantify the improvement in structural performance and the simultaneous increase in manufacturing time and resource consumption as cell size decreases, leading to the conclusion that the carbon footprint per unit strength or stiffness of the 6 mm cell is 2 to 3 times lower than that of the 12 mm cell. The trade-off between the conflicting requirements is presented in a performance map that serves as a decision-making tool in the current landscape where carbon footprint is being incorporated into product specifications alongside technical requirements.