Parametric design and performance study of continuous gradient triply periodic minimal surface bone scaffold

Continuous gradient triply periodic minimal surface (TPMS) porous structure has been proven to be one of the most suitable structures for bone implants due to their excellent mechanical properties and high porosity. This study establishes a parametric modeling method for continuous gradient TPMS structures and optimizes the TPMS porous structure with a continuous gradient change in porosity. Ti-6Al-4V continuous gradient TPMS porous structures were prepared using powder bed fusion (PBF). The mechanical properties and permeability of the continuous gradient TPMS porous structure were studied. The results indicate that the porosity control parameter C for gradient continuous change follows a linear function, with the porosity increasing linearly within the specified range of values. The influence of the periodic parameter ω on the mechanical properties and permeability of different types of TPMS structures varies. The Gyroid continuous gradient structure aligns more closely with the mechanical properties and permeability of bone scaffolds. Furthermore, a TPMS continuous gradient porous structure that is more suitable for trabecular bone implants was obtained through topology optimization design. A bone implant model and object suitable for human trabecular bone were designed and printed, providing technical support for subsequent performance testing and application research of bone implants.